feat: one Poll Lane per Site, replacing the shared pace (#100) (#106)

Closes #100.

Each Site runs its own Poll Lane: an independent goroutine with its own rest
and pace from the registry (`backend/internal/latest/sites.go`), replacing the
shared cooldown/interval/stagger/batch configuration. Rest (1h, all six Sites
including the browser trio) is enforced by the due query's WHERE clause; the
Lane sleeps its effective gap between fetches — the registry 10s, or
rest/eligible when a Site holds enough Series, floored at 1s with a
Site-naming warning when the floor engages.

Lane-local failure handling:
- Two challenge-held results stop that Site's Lane for 15m; the probes keep
  their stamp, untried Series stay due.
- A lost browser sets a shared Poller flag: the other browser Lanes skip
  their passes for the same 15m (no stamp-per-pass-per-Lane on a dead tab),
  then decay and probe again.
- Browser wake gate preserved (5 due, or one waiting 15m, ADR-0005); one tab
  shared by the three browser Sites; "browser lane behind by X" logged every
  pass.
- Cover work (healing a stored source URL and filling a blank from the series
  page) runs in the background so a slow CDN cannot consume a Lane's gap.

Removed: `LATEST_CHAPTER_POLL_{COOLDOWN,BROWSER_COOLDOWN,INTERVAL,BATCH,STAGGER}`
and the 6h browser rest. Only `LATEST_CHAPTER_POLL_ENABLED` remains; DEPLOY.md
documents the exact `.env` edit. ADR-0010 records the decisions.

Reviewed-on: #106
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

.env.example

@@ -73,26 +73,13 @@ DISCORD_REDIRECT_URI=
 # The backend re-checks each bookmarked series' newest published chapter on its
 # own schedule, so latest_chapter stays fresh even when you never open the manga
 # sites. This runs in parallel with the userscript's own in-browser check.
-# Set to 0 to turn it off entirely.
+# Set to 0 to turn it off entirely. Pace is per Site (one Poll Lane per Site,
+# issue #100) and lives in the backend registry, not here — there is nothing
+# else to configure.
 # LATEST_CHAPTER_POLL_ENABLED=1
 #
-# Two independent clocks. COOLDOWN is how long a plain-TLS series rests between
+# Every Site rests an hour between checks and gaps ten seconds between fetches;
-# checks; BROWSER_COOLDOWN is the longer rest for kagane and novelfull. INTERVAL
+# a Site with many Series tightens its own gap. See backend/internal/latest/sites.go.
-# is how often the poller wakes up and looks for series past their cooldowns.
-# Shortening INTERVAL cannot shorten either cooldown.
-LATEST_CHAPTER_POLL_COOLDOWN=1h         # plain-TLS per series, floor 15m
-LATEST_CHAPTER_POLL_BROWSER_COOLDOWN=6h # browser-backed per series, floor 15m
-LATEST_CHAPTER_POLL_INTERVAL=10m        # how often to wake
-LATEST_CHAPTER_POLL_BATCH=14            # series per wake
-LATEST_CHAPTER_POLL_STAGGER=20s         # delay between fetches in a batch
-#
-# Uses a ticker, not an immediate first run: the first poll happens one
-# INTERVAL after startup, not at startup. A container restarting more often
-# than INTERVAL never polls.
-#
-# BATCH x (COOLDOWN / INTERVAL) series hold the cooldown cadence — 84 with these
-# defaults. Beyond that the cadence stretches uniformly rather than breaking;
-# raise BATCH or lower INTERVAL. Keep BATCH x STAGGER under INTERVAL.
 
 # CDP endpoint of the browser, used for the two sites behind a Cloudflare
 # JavaScript challenge (kagane, novelfull) and by the web UI's kagane cover

CONTEXT.md

@@ -86,7 +86,7 @@ _Avoid_: client report, user poll, observation, claim
 
 **Acquisition**:
 The single read of a Series page made the moment the Series first exists, giving it
-both its Latest Chapter and its Cover without waiting out the Poll queue. Distinct
+both its Latest Chapter and its Cover without waiting for the Lane's pace. Distinct
 from a Poll in the two ways that matter: a Reader is present — it is triggered by
 their first Bookmark of that Series — and it is the only read that establishes a
 Cover rather than refreshing facts. It happens once in a Series's life; every later

DEPLOY.md

@@ -93,6 +93,14 @@ the backend dials but not the password the database expects, and `bookmark-api`
 crash-loops on `password authentication failed`. Set it before §2 and leave it
 alone.
 
+An `.env` written before issue #100 carries the old poll-pace names
+(`LATEST_CHAPTER_POLL_COOLDOWN`, `_BROWSER_COOLDOWN`, `_INTERVAL`, `_BATCH`,
+`_STAGGER`). All five are dead configuration now — the pace lives in the Site
+registry (`backend/internal/latest/sites.go`), so **delete those lines** and
+keep only the kill switch `LATEST_CHAPTER_POLL_ENABLED`. Leaving them behind
+is harmless (nothing reads them) but silently misleads the next person who
+edits the file.
+
 > Match `TRAEFIK_ENTRYPOINT` / `TRAEFIK_CERTRESOLVER` to your Traefik's actual
 > names (check your Traefik static config — common alternatives: `https`,
 > `myresolver`, `cloudflare`). Wrong names = no certificate issued.
@@ -505,7 +513,7 @@ picks up a restarted Chrome's new debugger UUID by itself.
 | kagane rows never get a `latest_chapter`; log says `browser fetcher disabled` or nothing at all | `BROWSER_WS_URL` unset. Expected before §7 is done. |
 | kagane polls all fail; log shows a 500 from `/json/version` | `BROWSER_WS_URL` names a MagicDNS hostname (or any name). Chrome's DevTools handler only accepts an IP or `localhost` — use the tailnet IP. |
 | kagane polls fail with a connection error | Home machine off, off the tailnet, or the unit is down. `tailscale ping <machine>`, then `docker compose ps` in its `chrome/`. Costs freshness only; stored covers keep serving. |
-| kagane cover is a placeholder for a newly bookmarked series | Its cover has never been fetched and the browser is unreachable. It fills in on the next successful poll of that series (up to `LATEST_CHAPTER_POLL_BROWSER_COOLDOWN`, default 6h). |
+| kagane cover is a placeholder for a newly bookmarked series | Its cover has never been fetched and the browser is unreachable. It fills in on the next successful poll of that series. |
 | `compose` in `chrome/` errors `set BROWSER_BIND_ADDR to this machine's tailnet IP` | No `chrome/.env`, or the variable is empty. Deliberate — it has no default so an unset value cannot publish CDP to the LAN. |
 | browser container restarts, or is OOM-killed | `docker inspect bookmark-browser --format '{{.RestartCount}} {{.State.OOMKilled}}'`. The 512 MiB cap is sized against a measured 645 MiB untuned peak; a real breach is a Chrome regression worth reading `docker logs` for, not a number to raise reflexively. |
 

README.md

@@ -53,12 +53,7 @@ covers are stored, so the library renders in full with the browser switched off.
 | `DISCORD_API_BASE` | `https://discord.com/api/v10` | Test seam — tests point it at a local stub so the real token exchange runs. |
 | `USERSCRIPT_PATH` | `/userscript/manga-bookmark.user.js` | Bindmounted file served at `/u/{token}/manga-bookmark.user.js`. |
 | `NOVEL_USERSCRIPT_PATH` | `/userscript/novel-bookmark.user.js` | Same, for the novel library. |
-| `LATEST_CHAPTER_POLL_ENABLED` | `1` | `0` turns the poller off entirely. |
+| `LATEST_CHAPTER_POLL_ENABLED` | `1` | `0` turns the poller off entirely. Pace is per Site in the registry — one Poll Lane per Site, each with its own rest and gap (issue #100) — so no other knobs exist. |
-| `LATEST_CHAPTER_POLL_COOLDOWN` | `1h` | Rest between checks of one plain-TLS series; floor `15m`. |
-| `LATEST_CHAPTER_POLL_BROWSER_COOLDOWN` | `6h` | Rest between checks of one browser-backed series; floor `15m`. |
-| `LATEST_CHAPTER_POLL_INTERVAL` | `10m` | How often the poller wakes. Cannot shorten either cooldown. |
-| `LATEST_CHAPTER_POLL_BATCH` | `14` | Series per wake. Keep `BATCH × STAGGER` under `INTERVAL`. |
-| `LATEST_CHAPTER_POLL_STAGGER` | `20s` | Delay between fetches in a batch — this is the outbound request rate. |
 
 Compose reads a few more from the same `.env` that the backend never sees:
 `POSTGRES_PASSWORD` (required — `DATABASE_URL` is built from it, and Postgres

backend/AGENTS.md

@@ -74,20 +74,33 @@ Guidance for OpenCode (and Claude Code) working under `backend/`. See root `AGEN
   Remove's row wear ember wash, two reversible ones wear `.calm` grey.
   `--ember` stay reserved for new-chapter signal: busy bar and inline
   error use `--mute`.
-- **Latest-chapter poller:** ticker goroutine in same binary re-check
+- **Latest-chapter poller:** one goroutine per Site (a Poll Lane, issue #100),
-  each bookmarked series' newest published chapter from backend's own
+  each re-checking that Site's bookmarked series' newest published chapter from
-  network access, so `latest_chapter` stay fresh when user not
+  backend's own network access, so `latest_chapter` stays fresh when the user
-  browsing. Second, parallel signal — userscript keep own
+  isn't browsing. Second, parallel signal — the userscript keeps its own
   `maybeCaptureLatestOnSeriesPage`/`backgroundRefreshLatest` logic unchanged.
-  Two independent clocks: per-series cooldown (`series.latest_checked_at`,
+  Two independent clocks: per-series rest (`series.latest_checked_at`,
-  enforced by `Store.DueForLatestCheck`'s WHERE clause) and wake interval.
+  enforced by `Store.DueForLatestCheck`'s WHERE clause — `now - Rest`) and
+  per-Lane gap (the Lane sleeping between fetches, `effectiveGap`). Both live
+  in the Site registry (`internal/latest/sites.go`), not config: the five env
+  knobs that used to size a shared pace are gone.
   The poller walks **Series, not Bookmarks** — a series referenced by several
   bookmarks is fetched once per cycle, and the due queue orders
   `reader_count DESC, latest_checked_at ASC` (ADR-0003). Series row stamped
-  *before* fetch so broken series wait out full cooldown instead of retrying
+  *before* fetch so broken series wait out the rest instead of retrying
   every tick; found chapter written straight to the series row via
   `Store.SetLatestChapter`, so a bookmark's `updated_at` — and the list
   order — is never touched.
+  Refusals and browser loss are Lane-local: two `errChallengeHeld` in one pass
+  stop that Site for `refuseBackoff` (15m) while other Lanes continue; an
+  `errBrowserInterrupted` (remote Chrome restart) sets a shared Poller flag
+  that makes the other browser Lanes skip their passes for the same 15m, so a
+  restarting Chrome doesn't stamp one Series per Lane per pass — after the
+  window the flag decays and they probe again. Browser Lanes wake Chrome only
+  when 5+ Series are due or one has waited 15m (ADR-0005 on-demand browser),
+  and cover work (both healing a stored source URL and filling a blank from
+  the series page) runs in the background so a slow CDN can't consume a
+  Lane's gap.
   Fetches use `bogdanfinn/tls-client` with Chrome profile as defence in depth
   against fingerprint-based blocking; any failure log and skip. kagane, comix
   and novelfull sit behind Cloudflare JavaScript challenges the TLS client
@@ -152,15 +165,17 @@ Guidance for OpenCode (and Claude Code) working under `backend/`. See root `AGEN
   `_REDIRECT_URI` (required; Discord OAuth for the browser UI),
   `DISCORD_REQUIRED_ROLE` (optional role gate, empty by default),
   `DISCORD_API_BASE` (default `https://discord.com/api/v10`),
-  `LATEST_CHAPTER_POLL_ENABLED`/`_COOLDOWN`/`_BROWSER_COOLDOWN`/`_INTERVAL`/
+  `LATEST_CHAPTER_POLL_ENABLED` (background latest-chapter poller kill
-  `_BATCH`/`_STAGGER` (background latest-chapter poller; defaults on,
+  switch, default on). Pace is per Site in the registry (issue #100): every
-  `1h` plain-TLS cooldown, `6h` browser cooldown, `10m`/`14`/`20s`; both
+  Site rests an hour and gaps ten seconds, a Site with more eligible Series
-  cooldowns have a `15m` floor). The browser cooldown is longer for cost, not
+  than 360 tightens its own gap toward the 1s floor, and browser Lanes wake
-  for safety: a challenged page costs seconds of a serialized single-tab
+  Chrome only on demand (ADR-0005). The `_COOLDOWN`/`_BROWSER_COOLDOWN`/
-  browser, while a plain read costs one request. It buys no documented
+  `_INTERVAL`/`_BATCH`/`_STAGGER` knobs that used to size a shared pace are
-  reduction in challenge risk — free-plan zones have no bot score and no
+  gone. The 1h rest for browser Sites is safe on documented grounds: a
-  published per-IP rate input, and `cf_clearance` expires in 30 minutes so
+  challenged page costs seconds of a serialized single-tab browser, free-plan
-  every cadence at or above 1h re-solves anyway —
+  zones have no bot score and no published per-IP rate input, and
+  `cf_clearance` expires in 30 minutes so every cadence at or above 1h
+  re-solves anyway —
   `docs/research/cloudflare-bot-scoring-and-poll-cadence.md`.
   `USERSCRIPT_PATH` and `NOVEL_USERSCRIPT_PATH` (files served at
   `/u/{token}/manga-bookmark.user.js` and `/u/{token}/novel-bookmark.user.js`,

backend/internal/latest/acquire.go

@@ -120,7 +120,7 @@ func (a *Acquirer) acquire(ctx context.Context, sr store.Series) {
 	// Stamped after success — the reverse of the poller, which stamps before
 	// the fetch: the Reader is here, watching the Series they just created, so
 	// a failed acquisition must leave the row due for a fast retry rather than
-	// consuming the cooldown. The stamp happens even when the page read
+	// consuming the rest. The stamp happens even when the page read
 	// succeeded but produced no facts to persist.
 	if err := a.Store.MarkLatestChecked(sr.Site, sr.SeriesID, time.Now().UnixMilli()); err != nil {
 		log.Printf("acquire %q: mark checked: %v", sr.Key(), err)

backend/internal/latest/browser.go

@@ -18,7 +18,7 @@ import (
 
 // challengeTimeout bounds one navigate-and-solve. A Cloudflare managed
 // challenge clears in a few seconds when it clears at all; anything longer is a
-// challenge that is not going to pass, and the caller's cooldown was already
+// challenge that is not going to pass, and the caller's rest was already
 // stamped before this ran.
 const challengeTimeout = 45 * time.Second
 
@@ -213,7 +213,7 @@ func (f *BrowserFetcher) Image(ctx context.Context, imageURL string) ([]byte, st
 
 // errChallengeHeld reports that the budget ran out with the interstitial still
 // up. Distinct from a transport failure: it means "this site said no", which
-// the poller answers with a 403 and its ordinary cooldown.
+// the poller answers with a refusal backoff for that Site's Lane (issue #100).
 var errChallengeHeld = errors.New("challenge held")
 
 // errBrowserInterrupted distinguishes a remote Chrome restart from the

backend/internal/latest/poller.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"log"
 	"net/url"
+	"sort"
+	"sync"
 	"time"
 
 	"bookmarkmanager/backend/internal/store"
@@ -28,15 +30,11 @@ type BrowserCoverFetcher interface {
 // in parallel and report the same observable fact, so whichever writes last wins
 // and neither needs to know about the other.
 //
-// Two clocks, deliberately independent:
+// Every Site gets its own Poll Lane: one independent stream of Polls with its
-//
+// own pace, running concurrently with every other Site's (issue #100). Rest
-//   - Interval is how often this goroutine wakes up and looks.
+// time and gap live in the Site registry, not here — see sites.go. Rest is
-//   - Cooldowns are how long a series rests since its own last check. Browser-
+// enforced by the WHERE clause in DueForLatestCheck rather than by any timer;
-//     backed sites use the longer BrowserCooldown.
+// the gap is enforced by the Lane sleeping between fetches.
-//
-// Cooldowns are enforced by the WHERE clause in DueForLatestCheck rather than
-// by any timer. Shortening Interval therefore cannot shorten anyone's cooldown;
-// it only makes the poller wake up and find nothing due more often.
 type Poller struct {
 	Store *store.Store
 	Fetch Fetcher
@@ -50,11 +48,19 @@ type Poller struct {
 	// same failure-isolated prefetch path.
 	CoverBytesFetch CoverBytesFetcher
 	Now             func() time.Time // injected so tests can freeze it
-	Cooldown        time.Duration
+
-	BrowserCooldown time.Duration
+	// refuseUntil gates a Site's Lane after it refused twice in one run: no
-	Interval        time.Duration
+	// Series of that Site is attempted again before this time (issue #100).
-	Stagger         time.Duration
+	// browserDownAt is when a browser Lane last lost the sidecar; the other
-	Batch           int
+	// browser Lanes skip their passes for the next refuseBackoff, so a
+	// restarting Chrome does not stamp one Series per pass per Lane (story 20).
+	mu            sync.Mutex
+	refuseUntil   map[string]time.Time
+	browserDownAt time.Time
+	// coverWG tracks in-flight cover work. Covers heal in the background so a
+	// slow cover host cannot delay the next Series-page Poll; tests join it
+	// before asserting on cover fetches.
+	coverWG sync.WaitGroup
 }
 
 // fillBlankCover gives a Series its Cover when it has none. The blank state is
@@ -76,7 +82,14 @@ func (p *Poller) fillBlankCover(ctx context.Context, sr store.Series, cover stri
 	if cover == "" {
 		return
 	}
-	p.storeCover(ctx, sr, cover)
+	// Like healCover, the fill runs in the background: a large import of
+	// blanks would otherwise pay one og:image fetch per Series against the
+	// Lane's gap (issue #100, story 12).
+	p.coverWG.Add(1)
+	go func() {
+		defer p.coverWG.Done()
+		p.storeCover(ctx, sr, cover)
+	}()
 }
 
 // prefetchCover heals Series that already carry a third-party source URL but
@@ -143,72 +156,248 @@ func fetcherFor(site string, browser, tls Fetcher) Fetcher {
 	return nil
 }
 
-// Run polls until ctx is cancelled.
+// Run polls until ctx is cancelled: one goroutine per Site Lane, each pacing
-//
+// itself by the Site's effective gap. Lanes share nothing but the store and
-// runOnce is called synchronously, so a batch that overruns the tick delays the
+// the browser fetcher's single tab (BrowserFetcher serializes itself), so one
-// next one instead of stacking a second batch on top of it. That is the intended
+// hostile Site burns only its own budget.
-// failure mode for a misconfigured batch x stagger: a slower cadence, never
+// laneNames returns every registry Site in the deterministic order both Run
-// concurrent fetch storms.
+// and runOnce iterate: sorted, so lane behaviour and its tests agree on who
+// runs first.
+func laneNames() []string {
+	names := make([]string, 0, len(sites))
+	for name := range sites {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
 func (p *Poller) Run(ctx context.Context) {
-	log.Printf("latest-chapter poller: interval=%s cooldown=%s browser-cooldown=%s batch=%d stagger=%s",
+	names := laneNames()
-		p.Interval, p.Cooldown, p.BrowserCooldown, p.Batch, p.Stagger)
+	log.Printf("latest-chapter poller: %d lanes, rest=%s gap=%s", len(names), defaultRest, defaultGap)
-	t := time.NewTicker(p.Interval)
+	for _, name := range names {
-	defer t.Stop()
+		go p.lane(ctx, name)
+	}
+	<-ctx.Done()
+	log.Println("latest-chapter poller: stopped")
+}
+
+// lane is one Site's Poll Lane: one pass, then sleep the pace the pass
+// reported, then another pass, until ctx is cancelled. The sleep is the whole
+// pace discipline — a pass that fetched nothing still reports its gap so the
+// Lane wakes often enough to notice Series as they become due. The pass shares
+// the Poller's browser-down state, so a sidecar loss is noticed once and the
+// other browser Lanes skip passes until the backoff window decays.
+func (p *Poller) lane(ctx context.Context, name string) {
 	for {
+		pace := p.runLanePass(ctx, name, true)
+		if ctx.Err() != nil {
+			return
+		}
 		select {
 		case <-ctx.Done():
-			log.Println("latest-chapter poller: stopped")
 			return
-		case <-t.C:
+		case <-time.After(pace):
-			p.runOnce(ctx)
 		}
 	}
 }
 
-// runOnce processes one batch of due series.
+// runOnce processes one round: one pass of every Lane, back to back, no real
+// time passing. This is the deterministic entry point the test suite drives a
+// round at a time. The production Run loop does the same work paced by its own
+// sleeps; pacing is the only difference.
 func (p *Poller) runOnce(ctx context.Context) {
+	for _, name := range laneNames() {
+		p.runLanePass(ctx, name, false)
+	}
+}
+
+// runLanePass processes one pass of one Site's Lane: select the due Series,
+// pace through them, and report how long the Lane should wait before its next
+// pass. paced spaces consecutive fetches by the Site's effective gap — the
+// production Lane's rate limit; the deterministic test entry runs back to back.
+func (p *Poller) runLanePass(ctx context.Context, name string, paced bool) time.Duration {
 	now := p.Now()
-	cutoff := now.Add(-p.Cooldown).UnixMilli()
+	if until := p.refusalBackoff(name); now.Before(until) {
-	browserCutoff := now.Add(-p.BrowserCooldown).UnixMilli()
+		// Cooling down after a refusal: do not attempt this Site at all.
-	due, err := p.Store.DueForLatestCheck(cutoff, browserCutoff, browserBackedSites(), p.Batch)
+		return until.Sub(now)
-	if err != nil {
+	}
-		log.Printf("latest poll: due query: %v", err)
+	if isBrowserSite(name) {
-		return
+		if downFor, down := p.browserDownFor(now); down && downFor < refuseBackoff {
+			// A sibling browser Lane lost the sidecar within the backoff
+			// window: skip this pass, so a restarting Chrome does not stamp
+			// this Site's Series one pass at a time. After refuseBackoff the
+			// flag decays and the Lane probes again (issue #100, story 20).
+			log.Printf("latest poll %s: browser lane skipping pass (sidecar down %s ago)", name, downFor)
+			return refuseBackoff - downFor
+		}
+	}
+	s := sites[name]
+	f := fetcherFor(name, p.BrowserFetch, p.Fetch)
+	if f == nil {
+		// No fetcher at all right now (browser absent, no fallback): every
+		// Series stays unstamped and due, so a browser that appears after a
+		// restart finds its full queue waiting (issue #100).
+		return defaultGap
 	}
 
+	due, err := p.Store.DueForLatestCheck(name, now.Add(-s.Rest).UnixMilli())
+	if err != nil {
+		log.Printf("latest poll %s: due query: %v", name, err)
+		return defaultGap
+	}
+	if s.Browser != nil && f == p.BrowserFetch && !browserWakeDue(due, now, s.Rest) {
+		// Below both thresholds Chrome stays asleep (ADR-0005 on-demand
+		// browser): waking it for a single Poll would cost a challenge solve
+		// per request.
+		return defaultGap
+	}
+	if s.Browser != nil {
+		// Browser Lanes share one tab, so their combined ceiling is about 360
+		// Polls an hour. When they cannot keep up, the wait past the rest time
+		// grows — log by how much, every pass, so the decision to give them
+		// more pages is made from a measurement rather than a guess.
+		if behind := maxSeriesWait(due, now, s.Rest) - s.Rest; behind > 0 {
+			log.Printf("latest poll %s: browser lane behind by %s (browser Sites cannot keep up with the hour)", name, behind)
+		}
+	}
+
+	eligible, err := p.Store.EligibleSeriesCount(name)
+	if err != nil {
+		log.Printf("latest poll %s: eligible count: %v", name, err)
+		return defaultGap
+	}
+	gap, clamped := effectiveGap(s, eligible)
+	if clamped {
+		log.Printf("latest poll %s: gap clamped to %s floor (eligible series=%d)", name, minGap, eligible)
+	}
+	if eligible == 0 {
+		// Nothing to poll for the foreseeable future; sleep a full rest instead
+		// of re-querying every gap.
+		return s.Rest
+	}
+
+	refusals := 0
 	checked := 0
 	for i, sr := range due {
 		if ctx.Err() != nil {
 			break
 		}
-		// Staggered rather than fired together: a burst of simultaneous requests
+		if refusals >= 2 {
-		// from one server IP is the traffic shape most likely to move that IP's
+			// This Site refused twice in a row: the remaining Series are left
-		// bot score. This is the server-side analogue of the userscript's "one
+			// unstamped and due, and the Lane waits refuseBackoff before
-		// series per navigation ... indistinguishable from browsing" (L455-456).
+			// trying it again.
-		stopped := false
-		if i > 0 && p.Stagger > 0 {
-			select {
-			case <-ctx.Done():
-				stopped = true
-			case <-time.After(p.Stagger):
-			}
-		}
-		if stopped {
 			break
 		}
-		p.checkOne(ctx, sr)
+		if paced && i > 0 {
+			select {
+			case <-ctx.Done():
+				break
+			case <-time.After(gap):
+			}
+			if ctx.Err() != nil {
+				break
+			}
+		}
+		if err := p.checkOne(ctx, sr); err != nil {
+			switch {
+			case errors.Is(err, errChallengeHeld):
+				refusals++
+			case errors.Is(err, errBrowserInterrupted):
+				p.setBrowserDown(now)
+				log.Printf("latest poll %s: browser unreachable, browser lanes skipping passes for %s", name, refuseBackoff)
+				return gap
+			default:
+				refusals = 0
+			}
+		} else {
+			refusals = 0
+		}
 		checked++
 	}
-	// due vs checked is how you tell which constraint is binding: ticks that
+	if checked > 0 {
-	// report due=0 mean the cooldown is the limit, ticks that report due==batch
+		log.Printf("latest poll %s: due=%d checked=%d", name, len(due), checked)
-	// every time mean throughput is.
+	}
-	log.Printf("latest poll: due=%d checked=%d", len(due), checked)
+	if refusals >= 2 {
+		p.setRefusalBackoff(name, now.Add(refuseBackoff))
+		log.Printf("latest poll %s: refused twice this run, waiting %s", name, refuseBackoff)
+		return refuseBackoff
+	}
+	return gap
+}
+
+func (p *Poller) refusalBackoff(name string) time.Time {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.refuseUntil[name]
+}
+
+func (p *Poller) setRefusalBackoff(name string, until time.Time) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.refuseUntil == nil {
+		p.refuseUntil = make(map[string]time.Time)
+	}
+	p.refuseUntil[name] = until
+}
+
+// setBrowserDown records when a browser Lane lost the sidecar. It is Poller
+// state rather than pass state so the other browser Lanes see it too.
+func (p *Poller) setBrowserDown(now time.Time) {
+	p.mu.Lock()
+	p.browserDownAt = now
+	p.mu.Unlock()
+}
+
+// browserDownFor reports how long the sidecar has been down and that it is
+// down at all — the zero time means never down, which must not read as a
+// zero-duration loss. The window decays: once refuseBackoff passes without a
+// fresh loss, Lanes probe again.
+func (p *Poller) browserDownFor(now time.Time) (time.Duration, bool) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.browserDownAt.IsZero() {
+		return 0, false
+	}
+	return now.Sub(p.browserDownAt), true
+}
+
+// isBrowserSite reports whether the registry routes this Site's page through
+// the browser sidecar.
+func isBrowserSite(name string) bool {
+	return sites[name].Browser != nil
+}
+
+// browserWakeDue reports whether a browser Lane may start a run: five or more
+// of its Series are due, or any one of them has been due for browserWakeAge.
+// Below both thresholds the Lane leaves Chrome asleep — Series Polled together
+// become due together, so the group naturally stays clustered, and the age
+// rule exists to stop a Series that drifted out of the group from starving.
+func browserWakeDue(due []store.Series, now time.Time, rest time.Duration) bool {
+	if len(due) >= browserWakeCount {
+		return true
+	}
+	return maxSeriesWait(due, now, rest) >= browserWakeAge
+}
+
+// maxSeriesWait returns how long the most-overdue of the due Series has been
+// waiting past its due moment (0 when due is empty).
+func maxSeriesWait(due []store.Series, now time.Time, rest time.Duration) time.Duration {
+	var oldest time.Duration
+	for _, sr := range due {
+		if w := now.Sub(time.UnixMilli(sr.LatestCheckedAt).Add(rest)); w > oldest {
+			oldest = w
+		}
+	}
+	return oldest
 }
 
 // checkOne re-checks one series. Every failure path here is "log and move on":
 // the poller is a best-effort enhancement, and no single bad series may stall a
-// batch or take down the process.
+// Lane or take down the process. The returned error is the page read's
-func (p *Poller) checkOne(ctx context.Context, sr store.Series) {
+// classified outcome so the Lane can tell a refusal from a loss of the
+// browser; non-classified failures still return nil-equivalent behaviour.
+func (p *Poller) checkOne(ctx context.Context, sr store.Series) error {
 	defer func() {
 		if r := recover(); r != nil {
 			log.Printf("latest poll %q: recovered from panic: %v", sr.Key(), r)
@@ -216,44 +405,46 @@ func (p *Poller) checkOne(ctx context.Context, sr store.Series) {
 	}()
 
 	// Stamped before the fetch, not after, so an error, a timeout, or a shutdown
-	// mid-request still consumes the cooldown. Otherwise a renamed or deleted
+	// mid-request still consumes the rest. Otherwise a renamed or deleted
-	// series would be retried on every single tick forever. The userscript
+	// series would be retried on every single pass forever. The userscript
-	// stamps in the same order and for the same reason (L471-473).
+	// stamps in the same order and for the same reason (L471-473). A Series
+	// never reaches checkOne without a fetcher — runLanePass skips those — so
+	// the stamp means "attempted", and an untried Series stays due.
 	if err := p.Store.MarkLatestChecked(sr.Site, sr.SeriesID, p.Now().UnixMilli()); err != nil {
 		log.Printf("latest poll %q: mark checked: %v", sr.Key(), err)
-		return
+		return nil
 	}
 
 	facts, err := readSeriesPage(ctx, sr.Site, sr.SeriesURL, p.BrowserFetch, p.Fetch)
 	if err != nil {
 		switch {
 		case errors.Is(err, errNotFetchable):
-			// The cooldown above is already consumed, so a row that never
+			// The rest above is already consumed, so a row that never
-			// passes the gate is retried at cooldown pace rather than
+			// passes the gate is retried at rest pace rather than
 			// hot-looping.
 			log.Printf("latest poll %q: not fetchable: site=%q url=%q", sr.Key(), sr.Site, sr.SeriesURL)
-			return
+			return err
 		case errors.Is(err, errNoFetcher):
 			log.Printf("latest poll %q: no fetcher for site %q", sr.Key(), sr.Site)
-			return
+			return err
 		}
 		// A legacy cover heals independently of the page read: its source may
 		// answer — a CDN — while the origin does not, so a fetch failure does
 		// not skip the heal, matching the order the shared read replaced.
-		p.prefetchCover(ctx, sr)
+		p.healCover(ctx, sr)
 		log.Printf("latest poll %q: %v", sr.Key(), err)
-		return
+		return err
 	}
 	// A legacy cover source is healed independently of the page read.
-	p.prefetchCover(ctx, sr)
+	p.healCover(ctx, sr)
 	// Cover fill is independent of the chapter signal: a page that lost its
 	// chapter list may keep its og:image, and a blank Series heals either way.
 	p.fillBlankCover(ctx, sr, facts.Cover)
 	if !facts.HasLatest {
 		// Most likely a challenge page or a layout change. Either way the row is
-		// already stamped, so this waits out a cooldown instead of hot-looping.
+		// already stamped, so this waits out a rest instead of hot-looping.
 		log.Printf("latest poll %q: no chapter links in %d bytes", sr.Key(), facts.BodyLen)
-		return
+		return nil
 	}
 
 	// Equality, not >, mirroring the userscript (L427): a site that retracts a
@@ -261,7 +452,7 @@ func (p *Poller) checkOne(ctx context.Context, sr store.Series) {
 	// against the due-query snapshot; a concurrent write in between only costs
 	// one redundant UPDATE of the same absolute value, never a wrong one.
 	if sr.LatestChapterNum != nil && *sr.LatestChapterNum == facts.Latest.Num {
-		return
+		return nil
 	}
 
 	// Series-level write: the row is shared, so one update refreshes every
@@ -270,9 +461,29 @@ func (p *Poller) checkOne(ctx context.Context, sr store.Series) {
 	// the list.
 	if err := p.Store.SetLatestChapter(sr.Site, sr.SeriesID, facts.Latest.Label, facts.Latest.Num); err != nil {
 		log.Printf("latest poll %q: set latest chapter: %v", sr.Key(), err)
-		return
+		return nil
 	}
 	log.Printf("latest poll %q: latest is now %s", sr.Key(), facts.Latest.Label)
+	return nil
+}
+
+// healCover runs prefetchCover in the background. Cover bytes come from a
+// different host — often a CDN — and heal once in a Series's life, so they
+// must not consume a Lane's gap: a large import with many blanks would
+// otherwise make every Latest Chapter go stale behind a slow image host
+// (issue #100).
+func (p *Poller) healCover(ctx context.Context, sr store.Series) {
+	p.coverWG.Add(1)
+	go func() {
+		defer p.coverWG.Done()
+		p.prefetchCover(ctx, sr)
+	}()
+}
+
+// waitCovers blocks until every in-flight cover heal finishes. Tests call it
+// after a round before asserting on cover fetches.
+func (p *Poller) waitCovers() {
+	p.coverWG.Wait()
 }
 
 // fetchableSeriesURL reports whether site is a Site the registry knows and

backend/internal/latest/poller_test.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"database/sql"
 	"errors"
+	"fmt"
 	"log"
 	"os"
 	"strings"
@@ -156,19 +157,16 @@ func (f *fakeBytesCoverFetcher) callCount() int {
 	return len(f.calls)
 }
 
-// newTestPoller wires a poller with a frozen clock and no stagger, so tests run
+// newTestPoller wires a poller with a frozen clock. Rest and gap come from the
-// instantly and deterministically.
+// Site registry, so tests seed checked_at relative to the one-hour rest; the
+// round entry point (runOnce) runs every Lane back to back with no real
+// pacing, so tests stay instant and deterministic.
 func newTestPoller(t *testing.T, s *store.Store, f Fetcher, at time.Time) *Poller {
 	t.Helper()
 	return &Poller{
-		Store:           s,
+		Store: s,
-		Fetch:           f,
+		Fetch: f,
-		Now:             func() time.Time { return at },
+		Now:   func() time.Time { return at },
-		Cooldown:        time.Hour,
-		BrowserCooldown: 6 * time.Hour,
-		Interval:        10 * time.Minute,
-		Stagger:         0,
-		Batch:           14,
 	}
 }
 
@@ -208,9 +206,10 @@ func TestRunOncePrefetchesPublicCover(t *testing.T) {
 	covers := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/jpeg"}
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200}, CoverBytesFetch: covers,
-		Now: func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, Batch: 10,
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if got := covers.callCount(); got != 1 {
 		t.Fatalf("cover fetch calls = %d, want 1", got)
@@ -241,9 +240,10 @@ func TestRunOnceDoesNotStoreNonImagePublicCover(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200},
 		CoverBytesFetch: &fakeBytesCoverFetcher{body: []byte("challenge"), contentType: "text/html"},
-		Now:             func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, Batch: 10,
+		Now:             func() time.Time { return time.UnixMilli(5_000_000) },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if _, _, found, err := s.GetCover(coverURL); err != nil || found {
 		t.Fatalf("non-image cover = found %v, err %v; want missing", found, err)
@@ -350,23 +350,6 @@ func TestRunOnceMarksCheckedOnFailure(t *testing.T) {
 	}
 }
 
-func TestRunOnceRespectsBatchLimit(t *testing.T) {
-	s, _ := newTestStore(t)
-	for i := 0; i < 20; i++ {
-		key := "asura:s" + string(rune('a'+i))
-		seedForCheck(t, s, key, "https://asurascans.com/comics/"+key, 0)
-	}
-
-	f := &fakeFetcher{body: "", status: 200}
-	p := newTestPoller(t, s, f, time.UnixMilli(5_000_000))
-	p.Batch = 5
-	p.runOnce(context.Background())
-
-	if got := f.callCount(); got != 5 {
-		t.Fatalf("fetched %d series, want 5 (batch limit)", got)
-	}
-}
-
 // The point of the split (ADR-0003): a series referenced by several bookmarks
 // is fetched once per due cycle, not once per bookmark. Two bookmarks share a
 // series when two readers track it (issue #22).
@@ -409,8 +392,8 @@ func TestRunOnceFetchesSharedSeriesOnce(t *testing.T) {
 	}
 }
 
-// One unreachable series must not abandon the rest of the batch.
+// One unreachable series must not abandon the rest of the Lane.
-func TestRunOnceOneBadSeriesDoesNotStallBatch(t *testing.T) {
+func TestRunOnceOneBadSeriesDoesNotStallLane(t *testing.T) {
 	s, _ := newTestStore(t)
 	keys := []string{"asura:a", "asura:b", "asura:c", "asura:d", "asura:e"}
 	for _, k := range keys {
@@ -436,7 +419,9 @@ func TestRunOnceOneBadSeriesDoesNotStallBatch(t *testing.T) {
 	}
 }
 
-func TestRunLogsCooldowns(t *testing.T) {
+// Pace now lives in the registry, not config: Run logs the lane defaults so a
+// deployment can see what the poller is doing without reading the source.
+func TestRunLogsLaneDefaults(t *testing.T) {
 	var logs strings.Builder
 	previous := log.Writer()
 	log.SetOutput(&logs)
@@ -444,21 +429,19 @@ func TestRunLogsCooldowns(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
-	(&Poller{
+	(&Poller{Now: func() time.Time { return time.Now() }}).Run(ctx)
-		Cooldown:        time.Hour,
-		BrowserCooldown: 6 * time.Hour,
-		Interval:        time.Hour,
-	}).Run(ctx)
 
-	if got := logs.String(); !strings.Contains(got, "cooldown=1h") ||
+	got := logs.String()
-		!strings.Contains(got, "browser-cooldown=6h") {
+	for _, want := range []string{"6 lanes", "rest=1h0m0s", "gap=10s"} {
-		t.Fatalf("startup log = %q, want both cooldowns", got)
+		if !strings.Contains(got, want) {
+			t.Fatalf("startup log = %q, want %q", got, want)
+		}
 	}
 }
 
-// The cooldown is enforced by the due query, so a second immediate pass must do
+// The rest is enforced by the due query, so a second immediate pass must do
-// nothing at all — this is what makes the tick interval independent of it.
+// nothing at all — this is what makes the Lane's sleep independent of it.
-func TestRunOnceHonoursCooldownAcrossPasses(t *testing.T) {
+func TestRunOnceHonoursRestAcrossPasses(t *testing.T) {
 	s, _ := newTestStore(t)
 	const url = "https://asurascans.com/comics/x"
 	seedForCheck(t, s, "asura:x", url, 0)
@@ -471,56 +454,18 @@ func TestRunOnceHonoursCooldownAcrossPasses(t *testing.T) {
 	if got := f.callCount(); got != 1 {
 		t.Fatalf("first pass fetched %d, want 1", got)
 	}
-	// Same instant, and again 59 minutes later: both inside the 1h cooldown.
+	// Same instant, and again 59 minutes later: both inside the 1h rest.
 	p.runOnce(context.Background())
 	p.Now = func() time.Time { return now.Add(59 * time.Minute) }
 	p.runOnce(context.Background())
 	if got := f.callCount(); got != 1 {
-		t.Fatalf("fetched %d times inside the cooldown, want 1", got)
+		t.Fatalf("fetched %d times inside the rest, want 1", got)
 	}
-	// Past the cooldown, it is due again.
+	// Past the rest, it is due again.
 	p.Now = func() time.Time { return now.Add(61 * time.Minute) }
 	p.runOnce(context.Background())
 	if got := f.callCount(); got != 2 {
-		t.Fatalf("fetched %d times after the cooldown, want 2", got)
+		t.Fatalf("fetched %d times after the rest, want 2", got)
-	}
-}
-
-func TestRunOnceUsesBrowserCooldown(t *testing.T) {
-	s, _ := newTestStore(t)
-	const browserKey = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
-	seedForCheck(t, s, "asura:plain", "https://asurascans.com/comics/plain", 0)
-	seedForCheck(t, s, browserKey, "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b", 0)
-
-	hour := time.Hour
-	now := time.Unix(2*int64(hour/time.Second), 0)
-	tls := &fakeFetcher{status: 200}
-	browser := &fakeFetcher{status: 200}
-	p := &Poller{
-		Store:           s,
-		Fetch:           tls,
-		BrowserFetch:    browser,
-		Now:             func() time.Time { return now },
-		Cooldown:        hour,
-		BrowserCooldown: 6 * hour,
-		Batch:           10,
-	}
-
-	p.runOnce(context.Background())
-	if got := tls.callCount(); got != 1 {
-		t.Fatalf("plain-TLS fetches after 2h = %d, want 1", got)
-	}
-	if got := browser.callCount(); got != 0 {
-		t.Fatalf("browser fetches after 2h = %d, want 0", got)
-	}
-
-	now = time.Unix(7*int64(hour/time.Second), 0)
-	p.runOnce(context.Background())
-	if got := tls.callCount(); got != 2 {
-		t.Fatalf("plain-TLS fetches after 7h = %d, want 2", got)
-	}
-	if got := browser.callCount(); got != 1 {
-		t.Fatalf("browser fetches after 7h = %d, want 1", got)
 	}
 }
 
@@ -665,17 +610,18 @@ func TestKaganeSkippedWhenNoBrowserFetcher(t *testing.T) {
 	f := &fakeFetcher{body: kaganeAPIFixture, status: 200}
 
 	p := &Poller{
-		Store:    s,
+		Store: s,
-		Fetch:    f,
+		Fetch: f,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now:   func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour,
-		Interval: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
 
 	if len(f.calls) != 0 {
 		t.Errorf("TLS fetcher was called for kagane: %v", f.calls)
 	}
+	if got := readLatestCheckedAt(t, s, "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"); got != 0 {
+		t.Errorf("latest_checked_at = %d, want 0 (untried stays due until a browser appears)", got)
+	}
 }
 
 // novelfull without a browser is not skipped outright: its challenge is a
@@ -699,11 +645,10 @@ func TestNovelfullUsesTLSWhenNoBrowserFetcher(t *testing.T) {
 	covers := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
 	p := &Poller{
 		Store: s, Fetch: tlsF, CoverBytesFetch: covers,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour,
-		Interval: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if len(tlsF.calls) != 1 {
 		t.Fatalf("TLS fetcher calls = %d, want 1", len(tlsF.calls))
@@ -741,9 +686,7 @@ func TestKaganeUsesBrowserFetcher(t *testing.T) {
 	browserF := &fakeFetcher{body: kaganeAPIFixture, status: 200}
 	p := &Poller{
 		Store: s, Fetch: tlsF, BrowserFetch: browserF,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour,
-		Interval: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
 
@@ -789,11 +732,10 @@ func TestComixUsesBrowserFetcher(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: tlsF, BrowserFetch: browserF,
 		CoverFetch: covers, CoverBytesFetch: tlsCovers,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour,
-		Interval: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if len(tlsF.calls) != 0 {
 		t.Errorf("TLS fetcher was called for comix: %v", tlsF.calls)
@@ -831,15 +773,16 @@ func TestComixSkippedWhenNoBrowserFetcher(t *testing.T) {
 	f := &fakeFetcher{body: comixSeriesFixture, status: 200}
 	p := &Poller{
 		Store: s, Fetch: f,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour,
-		Interval: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
 
 	if len(f.calls) != 0 {
 		t.Errorf("TLS fetcher was called for comix: %v", f.calls)
 	}
+	if got := readLatestCheckedAt(t, s, "comix:n8we-dungeons-and-crayons"); got != 0 {
+		t.Errorf("latest_checked_at = %d, want 0 (untried stays due until a browser appears)", got)
+	}
 }
 
 func TestRunOncePrefetchesKaganeCover(t *testing.T) {
@@ -860,10 +803,10 @@ func TestRunOncePrefetchesKaganeCover(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
 		BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200}, CoverFetch: covers,
-		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
-		Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	body, contentType, ok, err := s.CoverByAddress(store.CoverAddress(coverURL))
 	if err != nil || !ok {
@@ -898,11 +841,13 @@ func TestRunOnceDoesNotRefetchKaganeCover(t *testing.T) {
 	covers := &fakeCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
 	p := &Poller{
 		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200}, CoverFetch: covers,
-		Now: func() time.Time { return at }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+		Now: func() time.Time { return at },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 	at = at.Add(2 * time.Hour)
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if got := covers.callCount(); got != 1 {
 		t.Fatalf("cover fetch calls = %d, want 1 after two due cycles", got)
@@ -927,9 +872,10 @@ func TestRunOnceCoverFailureDoesNotBlockChapter(t *testing.T) {
 	p := &Poller{
 		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
 		CoverFetch: &fakeCoverFetcher{err: errors.New("browser unavailable")},
-		Now:        func() time.Time { return now }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+		Now:        func() time.Time { return now },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	got, found, err := s.Get(s.OwnerID(), key)
 	if err != nil || !found {
@@ -960,9 +906,10 @@ func TestRunOnceRejectsInvalidKaganeCover(t *testing.T) {
 	p := &Poller{
 		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
 		CoverFetch: &fakeCoverFetcher{body: []byte("not an image"), contentType: "text/html"},
-		Now:        func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+		Now:        func() time.Time { return time.UnixMilli(5_000_000) },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if _, _, found, err := s.CoverByAddress(store.CoverAddress(coverURL)); err != nil || found {
 		t.Fatalf("invalid cover persisted = %v, err %v; want missing", found, err)
@@ -985,9 +932,10 @@ func TestRunOnceWithoutCoverFetcherStillPollsKagane(t *testing.T) {
 	seedCoverSource(t, dbURL, "kagane", seriesID, coverURL)
 	p := &Poller{
 		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
-		Now: func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if _, _, found, err := s.CoverByAddress(store.CoverAddress(coverURL)); err != nil || found {
 		t.Fatalf("cover after nil CoverFetch = found %v, err %v; want missing", found, err)
@@ -1010,9 +958,10 @@ func TestRunOnceRoutesNonKaganeCoverToPublicFetcher(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200}, CoverFetch: browserCovers,
 		CoverBytesFetch: publicCovers,
-		Now:             func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+		Now:             func() time.Time { return time.UnixMilli(5_000_000) },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if got := publicCovers.callCount(); got != 1 {
 		t.Fatalf("public cover fetch calls = %d, want 1", got)
@@ -1128,10 +1077,10 @@ func TestRunOnceFillsBlankCoverFromSeriesPage(t *testing.T) {
 			p := &Poller{
 				Store: s, Fetch: page, BrowserFetch: page,
 				CoverBytesFetch: public, CoverFetch: browser,
-				Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+				Now: func() time.Time { return time.UnixMilli(5_000_000) },
-				Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
 			}
 			p.runOnce(context.Background())
+			p.waitCovers()
 
 			got := readBookmark(t, s, tc.key)
 			wantWire := testCoverBaseURL + "/covers/" + store.CoverAddress(tc.wantCover)
@@ -1181,7 +1130,7 @@ func TestRunOnceDoesNotReplaceExistingCover(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
 		CoverBytesFetch: public,
-		Now:             func() time.Time { return at }, Cooldown: time.Hour, Batch: 10,
+		Now:             func() time.Time { return at },
 	}
 	p.runOnce(context.Background())
 	at = at.Add(2 * time.Hour)
@@ -1216,9 +1165,10 @@ func TestRunOnceRetriesFailedBlankCoverOnNextPoll(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
 		CoverBytesFetch: public,
-		Now:             func() time.Time { return at }, Cooldown: time.Hour, Batch: 10,
+		Now:             func() time.Time { return at },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 	if got := readBookmark(t, s, key); got.Cover != "" {
 		t.Fatalf("Cover after failed fetch = %q, want blank", got.Cover)
 	}
@@ -1231,6 +1181,7 @@ func TestRunOnceRetriesFailedBlankCoverOnNextPoll(t *testing.T) {
 	public.contentType = "image/jpeg"
 	at = at.Add(2 * time.Hour)
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	if got := public.callCount(); got != 2 {
 		t.Fatalf("cover fetch calls after retry = %d, want 2", got)
@@ -1264,9 +1215,10 @@ func TestRunOnceBlankCoverFailureDoesNotBlockChapter(t *testing.T) {
 	p := &Poller{
 		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
 		CoverBytesFetch: &fakeBytesCoverFetcher{err: errors.New("cdn down")},
-		Now:             func() time.Time { return now }, Cooldown: time.Hour, Batch: 10,
+		Now:             func() time.Time { return now },
 	}
 	p.runOnce(context.Background())
+	p.waitCovers()
 
 	got := readBookmark(t, s, key)
 	if got.LatestChapterNum == nil || *got.LatestChapterNum != 181 {
@@ -1289,3 +1241,342 @@ const kaganeAPIFixtureWithCover = `
 {"book_id":"b","title":"Episode 41","chapter_no":"41","sort_no":41},
 {"book_id":"c","title":"Episode 40.5","chapter_no":"40.5","sort_no":40}]}
 `
+
+func TestEffectiveGap(t *testing.T) {
+	asura := sites["asura"]
+	tests := []struct {
+		eligible int
+		want     time.Duration
+		clamped  bool
+	}{
+		{0, 10 * time.Second, false},
+		{5, 10 * time.Second, false},
+		{360, 10 * time.Second, false},
+		{720, 5 * time.Second, false},
+		{3600, time.Second, false},
+		{4000, time.Second, true},
+	}
+	for _, tt := range tests {
+		got, clamped := effectiveGap(asura, tt.eligible)
+		if got != tt.want || clamped != tt.clamped {
+			t.Errorf("effectiveGap(asura, %d) = (%s, %v), want (%s, %v)",
+				tt.eligible, got, clamped, tt.want, tt.clamped)
+		}
+	}
+}
+
+// The due query orders by sharedness first, then age: a series two readers
+// track is polled before a single-reader series that has waited far longer
+// (ADR-0003, issue #100).
+func TestRunOnceOrdersBySharednessThenAge(t *testing.T) {
+	s, url := newTestStore(t)
+	other, err := store.Open(url, store.Owner{DiscordID: "second-reader", TokenHash: sha256.Sum256([]byte("second-token-hash"))}, t.TempDir(), testCoverBaseURL)
+	if err != nil {
+		t.Fatalf("Open second reader: %v", err)
+	}
+	t.Cleanup(func() { other.Close() })
+
+	now := time.UnixMilli(5_000_000)
+	// popular: two readers, due for 2 minutes. loner: one reader, due for 23
+	// minutes. Popularity must win — the loner waited far longer.
+	const (
+		popularKey = "asura:popular"
+		lonerKey   = "asura:loner"
+		popularURL = "https://asurascans.com/comics/popular"
+		lonerURL   = "https://asurascans.com/comics/loner"
+	)
+	seedForCheck(t, s, popularKey, popularURL, now.Add(-62*time.Minute).UnixMilli())
+	seedForCheck(t, s, lonerKey, lonerURL, 0)
+	if _, err := s.Upsert(other.OwnerID(), store.Bookmark{
+		Key: popularKey, Site: "asura", SeriesID: "popular", UpdatedAt: 2000,
+	}); err != nil {
+		t.Fatalf("seed second reader: %v", err)
+	}
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	newTestPoller(t, s, f, now).runOnce(context.Background())
+
+	if len(f.calls) != 2 {
+		t.Fatalf("fetches = %d, want 2", len(f.calls))
+	}
+	if f.calls[0] != popularURL {
+		t.Fatalf("first fetch = %q, want the shared series %q", f.calls[0], popularURL)
+	}
+}
+
+// Two refusals in one pass stop the Lane: the remaining Series stay unstamped
+// and due, and the Lane backs off for refuseBackoff before trying the Site
+// again. One hostile Site burns only its own Lane's budget (issue #100).
+func TestRunOnceSiteRefusalSkipsRestOfLaneAndBacksOff(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(5_000_000)
+	const n = 4
+	for i := 0; i < n; i++ {
+		key := fmt.Sprintf("kagane:s%d", i)
+		seedForCheck(t, s, key, "https://kagane.to/series/"+key[7:], 0)
+	}
+
+	browser := &fakeFetcher{status: 403}
+	tls := &fakeFetcher{status: 200}
+	// An asura Series sits on its own Lane: it must still be polled while
+	// kagane's Lane burns its budget on refusals (story 4).
+	seedForCheck(t, s, "asura:still-polls", "https://asurascans.com/series/still-polls", 0)
+	p := &Poller{
+		Store: s, Fetch: tls, BrowserFetch: browser,
+		Now: func() time.Time { return now },
+	}
+
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 2 {
+		t.Fatalf("browser fetches after first pass = %d, want 2 (refused twice)", got)
+	}
+	if got := tls.callCount(); got != 1 {
+		t.Fatalf("asura fetches after first pass = %d, want 1 (its Lane is independent)", got)
+	}
+	stamped := 0
+	for i := 0; i < n; i++ {
+		if readLatestCheckedAt(t, s, fmt.Sprintf("kagane:s%d", i)) == now.UnixMilli() {
+			stamped++
+		}
+	}
+	if stamped != 2 {
+		t.Fatalf("stamped series = %d, want 2; the remaining two stay due", stamped)
+	}
+
+	// Inside the backoff window nothing is attempted.
+	p.Now = func() time.Time { return now.Add(14 * time.Minute) }
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 2 {
+		t.Fatalf("browser fetches inside backoff = %d, want still 2", got)
+	}
+
+	// Past the backoff the Lane resumes and the two untried Series are polled.
+	p.Now = func() time.Time { return now.Add(16 * time.Minute) }
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 4 {
+		t.Fatalf("browser fetches after backoff = %d, want 4", got)
+	}
+	for i := 0; i < n; i++ {
+		if got := readLatestCheckedAt(t, s, fmt.Sprintf("kagane:s%d", i)); got == 0 {
+			t.Fatalf("kagane:s%d still untried after backoff", i)
+		}
+	}
+}
+
+// Below five due Series with none waiting long, a browser Lane leaves Chrome
+// asleep; five due, or one waiting browserWakeAge, wakes it (ADR-0005).
+func TestBrowserLaneWakeThresholds(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(5_000_000)
+	// Freshly due: checked two minutes before the rest elapses, so the wait
+	// is far below browserWakeAge.
+	seed := func(i int) {
+		key := fmt.Sprintf("kagane:w%d", i)
+		seedForCheck(t, s, key, "https://kagane.to/series/"+key[7:], now.Add(-62*time.Minute).UnixMilli())
+	}
+	for i := 0; i < 3; i++ {
+		seed(i)
+	}
+
+	browser := &fakeFetcher{body: kaganeAPIFixture, status: 200}
+	p := &Poller{
+		Store: s, Fetch: &fakeFetcher{status: 200}, BrowserFetch: browser,
+		Now: func() time.Time { return now },
+	}
+
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 0 {
+		t.Fatalf("browser fetches with 3 freshly-due series = %d, want 0 (Chrome stays asleep)", got)
+	}
+	// 5 due crosses the count threshold.
+	for i := 3; i < 5; i++ {
+		seed(i)
+	}
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 5 {
+		t.Fatalf("browser fetches with 5 due series = %d, want 5", got)
+	}
+	// A single long-neglected series wakes the browser by age alone.
+	seedForCheck(t, s, "kagane:ancient", "https://kagane.to/series/ancient", 0)
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 6 {
+		t.Fatalf("browser fetches with one ancient series = %d, want 6", got)
+	}
+}
+
+// When one browser Lane loses the sidecar, the round's remaining browser
+// Lanes are skipped: every fetch would fail anyway, and their Series must not
+// burn their stamps on a dead Chrome (issue #100).
+func TestRunOnceUnreachableBrowserStopsBrowserLanes(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(5_000_000)
+	seedForCheck(t, s, "comix:c", "https://comix.to/title/c", 0)
+	seedForCheck(t, s, "kagane:k", "https://kagane.to/series/k", 0)
+	seedForCheck(t, s, "novelfull:n", "https://novelfull.com/n.html", 0)
+
+	interrupted := fmt.Errorf("%w: %w", errBrowserInterrupted, errors.New("restart"))
+	browser := &fakeFetcher{status: 200, err: interrupted}
+	p := &Poller{
+		Store: s, Fetch: &fakeFetcher{status: 200}, BrowserFetch: browser,
+		Now: func() time.Time { return now },
+	}
+	p.runOnce(context.Background())
+
+	// Sorted lane order: comix, kagane, novelfull. Only comix attempted.
+	if got := browser.callCount(); got != 1 {
+		t.Fatalf("browser fetches = %d, want 1 (only the first browser lane)", got)
+	}
+	if got := readLatestCheckedAt(t, s, "comix:c"); got != now.UnixMilli() {
+		t.Fatalf("comix stamp = %d, want %d", got, now.UnixMilli())
+	}
+	for _, key := range []string{"kagane:k", "novelfull:n"} {
+		if got := readLatestCheckedAt(t, s, key); got != 0 {
+			t.Fatalf("%s stamp = %d, want 0 (untried)", key, got)
+		}
+	}
+
+	// The shared flag decays after refuseBackoff: the next round probes
+	// again. comix's Series is resting (stamped last round), so the probe
+	// falls to kagane — the only Lane with something due — and its fresh
+	// loss re-gates the Lanes behind it.
+	p.Now = func() time.Time { return now.Add(16 * time.Minute) }
+	p.runOnce(context.Background())
+	if got := browser.callCount(); got != 2 {
+		t.Fatalf("browser fetches after backoff decay = %d, want 2 (kagane probes again)", got)
+	}
+	if got := readLatestCheckedAt(t, s, "comix:c"); got != now.UnixMilli() {
+		t.Fatalf("comix stamp after decay = %d, want %d (resting, untouched)", got, now.UnixMilli())
+	}
+	if got := readLatestCheckedAt(t, s, "kagane:k"); got != now.Add(16*time.Minute).UnixMilli() {
+		t.Fatalf("kagane stamp after decay = %d, want %d (the probe)", got, now.Add(16*time.Minute).UnixMilli())
+	}
+	if got := readLatestCheckedAt(t, s, "novelfull:n"); got != 0 {
+		t.Fatalf("novelfull stamp after decay = %d, want 0 (gated by kagane's fresh loss)", got)
+	}
+}
+
+// A browser Lane that cannot keep up logs the backlog every pass, so the
+// decision to give browser Sites more pages is measured, not guessed.
+func TestRunOnceLogsBrowserLaneBehind(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(5_000_000)
+	// Checked three rests ago: two rests' worth of wait past the due moment.
+	seedForCheck(t, s, "kagane:old", "https://kagane.to/series/old", now.Add(-3*time.Hour).UnixMilli())
+
+	var logs strings.Builder
+	prev := log.Writer()
+	log.SetOutput(&logs)
+	t.Cleanup(func() { log.SetOutput(prev) })
+
+	p := &Poller{
+		Store: s, Fetch: &fakeFetcher{status: 200},
+		BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
+		Now:          func() time.Time { return now },
+	}
+	p.runOnce(context.Background())
+
+	if got := logs.String(); !strings.Contains(got, "latest poll kagane: browser lane behind by 1h0m0s") {
+		t.Fatalf("behind log = %q, want it to name kagane and the backlog", got)
+	}
+}
+
+// gatedCoverFetcher blocks every Fetch on a gate, so a test can hold a cover
+// heal in flight and prove a Lane does not wait for it.
+type gatedCoverFetcher struct {
+	inner   *fakeBytesCoverFetcher
+	gate    chan struct{}
+	started chan struct{}
+	once    sync.Once
+}
+
+func (g *gatedCoverFetcher) Fetch(ctx context.Context, sourceURL string) ([]byte, string, error) {
+	g.once.Do(func() { g.started <- struct{}{} })
+	<-g.gate
+	return g.inner.Fetch(ctx, sourceURL)
+}
+
+// Cover heals run in the background: a heal stuck on a slow CDN must not
+// delay the Lane's next Series-page Poll, or a large import with many blanks
+// would make every Latest Chapter go stale (issue #100).
+func TestRunOnceCoverFetchDoesNotDelayNextPoll(t *testing.T) {
+	s, dbURL := newTestStore(t)
+	// Two Series whose legacy cover sources still need healing.
+	for i := 0; i < 2; i++ {
+		key := fmt.Sprintf("asura:cover-%d", i)
+		seriesID := fmt.Sprintf("cover-%d", i)
+		if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+			Key: key, Site: "asura", SeriesID: seriesID,
+			SeriesURL: "https://asurascans.com/comics/" + seriesID, UpdatedAt: 1000,
+		}); err != nil {
+			t.Fatalf("seed: %v", err)
+		}
+		seedCoverSource(t, dbURL, "asura", seriesID, fmt.Sprintf("https://cdn.example/covers/%d.jpg", i))
+	}
+
+	pages := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	gated := &gatedCoverFetcher{
+		inner:   &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/jpeg"},
+		gate:    make(chan struct{}),
+		started: make(chan struct{}, 1),
+	}
+	p := &Poller{
+		Store: s, Fetch: pages, CoverBytesFetch: gated,
+		Now: func() time.Time { return time.UnixMilli(5_000_000) },
+	}
+
+	done := make(chan struct{})
+	go func() {
+		p.runOnce(context.Background())
+		close(done)
+	}()
+	<-gated.started // the first cover heal is now stuck on its CDN
+	select {
+	case <-done:
+		// The Lane finished its page fetches without waiting for the cover.
+	case <-time.After(5 * time.Second):
+		t.Fatal("runOnce blocked on an in-flight cover fetch")
+	}
+	close(gated.gate)
+	p.waitCovers()
+
+	if got := pages.callCount(); got != 2 {
+		t.Fatalf("series page fetches = %d, want 2", got)
+	}
+	if got := gated.inner.callCount(); got != 2 {
+		t.Fatalf("cover fetches = %d, want 2", got)
+	}
+}
+
+// At 3601 eligible Series the effective gap falls below the one-second floor;
+// the clamp warning must name the Site so the operator knows which Lane is
+// outrunning its plan.
+func TestRunOnceClampWarningNamesTheSite(t *testing.T) {
+	s, dbURL := newTestStore(t)
+	db, err := sql.Open("pgx", dbURL)
+	if err != nil {
+		t.Fatalf("open %s: %v", dbURL, err)
+	}
+	defer db.Close()
+	if _, err := db.Exec(`INSERT INTO series (site, series_id, series_url, latest_checked_at)
+		SELECT 'asura', 'bulk-' || g, 'https://asurascans.com/comics/bulk-' || g, 0
+		FROM generate_series(1, 3601) AS g`); err != nil {
+		t.Fatalf("bulk seed series: %v", err)
+	}
+	if _, err := db.Exec(`INSERT INTO bookmarks (reader_id, site, series_id, updated_at)
+		SELECT (SELECT id FROM readers ORDER BY id LIMIT 1), 'asura', 'bulk-' || g, 1000
+		FROM generate_series(1, 3601) AS g`); err != nil {
+		t.Fatalf("bulk seed bookmarks: %v", err)
+	}
+
+	var logs strings.Builder
+	prev := log.Writer()
+	log.SetOutput(&logs)
+	t.Cleanup(func() { log.SetOutput(prev) })
+
+	newTestPoller(t, s, &fakeFetcher{body: "<html></html>", status: 200}, time.UnixMilli(5_000_000)).
+		runOnce(context.Background())
+
+	if got := logs.String(); !strings.Contains(got, "latest poll asura: gap clamped to 1s floor (eligible series=3601)") {
+		t.Fatalf("clamp warning = %q, want it to name asura and 3601", got)
+	}
+}

backend/internal/latest/read.go

@@ -9,7 +9,7 @@ import (
 // seriesRead carries the two facts the poll and the acquirer both extract
 // from a series page. Persistence, stamps and scheduling stay with the
 // callers, so the policies that keep the two flows distinct (stamp order,
-// cooldowns) are not swallowed by the module.
+// rests) are not swallowed by the module.
 type seriesRead struct {
 	Latest    latestChapter
 	HasLatest bool
@@ -22,6 +22,9 @@ type seriesRead struct {
 
 // errNotFetchable and errNoFetcher separate the gate and the route from fetch
 // failures so each caller keeps its own distinct log line for all three.
+// errChallengeHeld (browser.go) is the outcome of a Site that answered with
+// its interstitial — status 403 (cf-mitigated) or a challenge page body — and
+// is how a Lane tells a refusal from an ordinary failure (issue #100).
 var (
 	errNotFetchable = errors.New("series url not fetchable")
 	errNoFetcher    = errors.New("no fetcher for site")
@@ -49,9 +52,21 @@ func readSeriesPage(ctx context.Context, site, seriesURL string, browser, tls Fe
 	if err != nil {
 		return seriesRead{}, fmt.Errorf("fetch %s: %w", seriesURL, err)
 	}
+	if status == 403 {
+		// Cloudflare's challenge response for these Sites (cf-mitigated). The
+		// browser fetcher returns exactly this on a held interstitial, and a
+		// plain-TLS 403 means the same: the Site is refusing.
+		return seriesRead{}, fmt.Errorf("%w: fetch %s: status %d", errChallengeHeld, seriesURL, status)
+	}
 	if status != 200 {
 		return seriesRead{}, fmt.Errorf("fetch %s: status %d", seriesURL, status)
 	}
+	if isInterstitial(body) {
+		// A 200 that is the challenge page, not the payload: the TLS route can
+		// receive this where the browser would have kept re-reading. Same
+		// refusal as the 403.
+		return seriesRead{}, fmt.Errorf("%w: fetch %s: interstitial body", errChallengeHeld, seriesURL)
+	}
 	latest, hasLatest := latestChapterFrom(site, seriesURL, body)
 	cover, hasCover := coverFrom(site, seriesURL, body)
 	return seriesRead{Latest: latest, HasLatest: hasLatest, Cover: cover, HasCover: hasCover, BodyLen: len(body)}, nil

backend/internal/latest/sites.go

@@ -9,6 +9,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/chromedp/chromedp"
 )
@@ -32,6 +33,11 @@ type site struct {
 	LatestChapter func(seriesURL, body string) (latestChapter, bool)
 	// Cover finds the Cover address in a fetched body.
 	Cover func(seriesURL, body string) (string, bool)
+	// Rest is how long a Series of this Site rests between Polls.
+	Rest time.Duration
+	// Gap is the Lane's strictest pace: at least one second must pass between
+	// two consecutive Series-page Polls of this Site (issue #100).
+	Gap time.Duration
 	// Browser reads this Site's payload from a cleared browser tab; nil
 	// means the page is fetched over plain TLS.
 	Browser *browserRead
@@ -380,6 +386,50 @@ func publishedCoverURL(value string) string {
 	return strings.ReplaceAll(value, " ", "%20")
 }
 
+// Poll Lane constants (issue #100). The per-Site structure is deliberately
+// uniform at first — every Site rests an hour and gaps ten seconds — but it
+// exists so a single Site can be slowed if it turns hostile, and the numbers
+// stay in the registry so the structure has a place to differ.
+const (
+	// defaultRest is how long every Series rests between Polls.
+	defaultRest = time.Hour
+	// defaultGap is the strictest pace of every Lane unless the eligible
+	// Series count forces it tighter.
+	defaultGap = 10 * time.Second
+	// minGap floors the effective gap. One request per second is already an
+	// order of magnitude past the strictest rate rule a free-plan Site can
+	// express (docs/research/cloudflare-bot-scoring-and-poll-cadence.md);
+	// below it the Lane is outrunning its own plan and says so loudly.
+	minGap = time.Second
+	// refuseBackoff is how long a Lane waits after its Site refused twice in
+	// one run before attempting it again.
+	refuseBackoff = 15 * time.Minute
+	// browserWakeCount and browserWakeAge gate a browser Lane's run: five or
+	// more due Series, or any one of them waiting this long, or Chrome stays
+	// asleep (ADR-0005 on-demand browser).
+	browserWakeCount = 5
+	browserWakeAge   = 15 * time.Minute
+)
+
+// effectiveGap is a Site's pace: the registry gap, or one rest divided by the
+// eligible Series count when that is smaller, never below one second. The
+// denominator follows defaultRest rather than a literal hour so a Site whose
+// rest is ever changed keeps its per-Series pace in step. The second return is
+// true when the one-second floor engaged (and the Lane logs a warning naming
+// the Site, every round it does).
+func effectiveGap(s site, eligible int) (time.Duration, bool) {
+	gap := s.Gap
+	if eligible > 0 {
+		if perSeries := defaultRest / time.Duration(eligible); perSeries < gap {
+			gap = perSeries
+		}
+	}
+	if gap < minGap {
+		return minGap, true
+	}
+	return gap, false
+}
+
 // sites is the registry: one entry per Site, keyed by the stored site string.
 // Adding a Site means adding an entry here and nowhere else — the dispatch
 // functions above and the poller's route list are lookups into this map. An
@@ -390,16 +440,22 @@ var sites = map[string]site{
 		Host:          "asurascans.com",
 		LatestChapter: asuraLatestChapter,
 		Cover:         ogImageCover,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 	},
 	"demonic": {
 		Host:          "demonicscans.org",
 		LatestChapter: demonicLatestChapter,
 		Cover:         ogImageCover,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 	},
 	"comix": {
 		Host:          "comix.to",
 		LatestChapter: comixLatestChapter,
 		Cover:         comixCoverEntry,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 		Browser: &browserRead{
 			Read: comixRead,
 			// The interstitial is served in place of the page, so "arrived"
@@ -414,6 +470,8 @@ var sites = map[string]site{
 		Host:          "kagane.to",
 		LatestChapter: kaganeLatestChapter,
 		Cover:         kaganeCoverEntry,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 		Browser: &browserRead{
 			Read: kaganeRead,
 			Done: func(body string) bool { return body != "" },
@@ -426,6 +484,8 @@ var sites = map[string]site{
 		Host:          "novelfull.com",
 		LatestChapter: novelfullLatestChapter,
 		Cover:         novelfullCoverEntry,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 		Browser: &browserRead{
 			Read: novelfullRead,
 			// The interstitial has a DOM too, so "the payload arrived" has to
@@ -438,13 +498,15 @@ var sites = map[string]site{
 		Host:          "lightnovelworld.net",
 		LatestChapter: lnwLatestChapter,
 		Cover:         ogImageCover,
+		Rest:          defaultRest,
+		Gap:           defaultGap,
 	},
 }
 
 // browserBackedSites is derived from the registry: the Sites whose pages are
-// read through the browser sidecar, which are also the ones granted the longer
+// read through the browser sidecar. Sorted so callers that range it (the
-// cooldown. Sorted so callers that range it (the due query, the browser
+// browser fetcher's dispatch) see a stable order instead of map-iteration
-// fetcher's dispatch) see a stable order instead of map-iteration noise.
+// noise.
 func browserBackedSites() []string {
 	out := make([]string, 0, len(sites))
 	for name, s := range sites {

backend/internal/store/store.go

@@ -16,7 +16,6 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/jackc/pgx/v5/pgtype"
 	_ "github.com/jackc/pgx/v5/stdlib"
 )
 
@@ -39,7 +38,7 @@ type Bookmark struct {
 	// origin once the bytes exist, and "" until they do — never a third-party
 	// address and never an address that 404s (ADR-0007). A client may still
 	// send this field and it is discarded on the way in; see Upsert.
-	Cover string `json:"cover"`
+	Cover            string   `json:"cover"`
 	LastChapter      string   `json:"last_chapter"`
 	LastChapterNum   float64  `json:"last_chapter_num"`
 	LastChapterURL   string   `json:"last_chapter_url"`
@@ -897,10 +896,13 @@ func (s *Store) Delete(readerID int64, key string) error {
 	return nil
 }
 
-// DueForLatestCheck returns series whose server-side latest-chapter check has
+// DueForLatestCheck returns one Site's series whose server-side
-// aged past the appropriate cutoff, ordered by how many bookmarks reference
+// latest-chapter check has aged past cutoffMs, ordered by how many bookmarks
-// them (descending) then least-recently-checked first, at most limit of them.
+// reference them (descending) then least-recently-checked first. One Site per
-// Browser-backed sites use browserCutoffMs; every other site uses cutoffMs.
+// query, because each Poll Lane asks for its own list: the query carries one
+// Site and one cut-off instead of parallel lists (issue #100). There is no
+// limit — the Lane's own gap paces the fetches, and the batch size that used
+// to cap this query is gone with the shared pace.
 //
 // The reader_count ordering is the point of the split (ADR-0003): a series
 // shared by several readers is fetched once per due cycle, and the popular
@@ -916,20 +918,17 @@ func (s *Store) Delete(readerID int64, key string) error {
 // burns requests. Archived bookmarks still count — knowing what a shelved
 // series is up to is the whole reason for archiving instead of deleting.
 // A series with no bookmarks at all never appears: the join excludes it.
-func (s *Store) DueForLatestCheck(cutoffMs, browserCutoffMs int64, browserSites []string, limit int) ([]Series, error) {
+func (s *Store) DueForLatestCheck(site string, cutoffMs int64) ([]Series, error) {
 	rows, err := s.db.Query(`SELECT `+seriesColumns+`, COUNT(*) AS reader_count
 		FROM series s
 		JOIN bookmarks b ON b.site = s.site AND b.series_id = s.series_id
-		WHERE s.series_url <> ''
+		WHERE s.site = $1
-		  AND s.latest_checked_at <= CASE
+		  AND s.series_url <> ''
-			WHEN s.site = ANY($3::text[]) THEN $2::bigint
+		  AND s.latest_checked_at <= $2::bigint
-			ELSE $1::bigint
-		  END
 		GROUP BY s.site, s.series_id, s.title, s.series_url, s.cover,
 		         s.kind, s.latest_chapter, s.latest_chapter_num, s.latest_checked_at
 		HAVING COUNT(*) FILTER (WHERE b.status <> 'finished') > 0
-		ORDER BY reader_count DESC, s.latest_checked_at ASC
+		ORDER BY reader_count DESC, s.latest_checked_at ASC`, site, cutoffMs)
-		LIMIT $4`, cutoffMs, browserCutoffMs, pgtype.FlatArray[string](browserSites), limit)
 	if err != nil {
 		return nil, fmt.Errorf("query due series: %w", err)
 	}
@@ -946,6 +945,30 @@ func (s *Store) DueForLatestCheck(cutoffMs, browserCutoffMs int64, browserSites
 	return out, rows.Err()
 }
 
+// EligibleSeriesCount returns how many of a Site's Series still have at least
+// one bookmark outside the finished bucket. It is the denominator of the
+// Lane's pace (issue #100): the effective gap is the smaller of the registry
+// gap and one hour divided by this count, so Series that will never be Polled
+// do not make the Lane faster than it needs to be, and counting every eligible
+// Series rather than only those currently due keeps the pace steady — the
+// single worst moment to be fastest is startup, when everything is due at
+// once.
+func (s *Store) EligibleSeriesCount(site string) (int, error) {
+	var n int
+	err := s.db.QueryRow(`SELECT COUNT(*) FROM (
+		SELECT 1
+		FROM series s
+		JOIN bookmarks b ON b.site = s.site AND b.series_id = s.series_id
+		WHERE s.site = $1
+		GROUP BY s.site, s.series_id
+		HAVING COUNT(*) FILTER (WHERE b.status <> 'finished') > 0
+	) e`, site).Scan(&n)
+	if err != nil {
+		return 0, fmt.Errorf("count eligible series %s: %w", site, err)
+	}
+	return n, nil
+}
+
 // MarkLatestChecked records that the server looked at a series at ts, whatever
 // the look turned up. Marking a missing series is not an error: the row may
 // have been orphaned while a fetch was in flight.
@@ -954,7 +977,7 @@ func (s *Store) DueForLatestCheck(cutoffMs, browserCutoffMs int64, browserSites
 // out of the client-visible read path on purpose. PUT /bookmarks/{key} decodes
 // a whole Bookmark from the client and Upsert writes every series column it
 // knows about, so a userscript PUT — which has no idea this field exists —
-// would write a zero and reset the cooldown, making the poller re-fetch that
+// would write a zero and reset the rest, making the poller re-fetch that
 // series every tick for as long as the user kept reading it.
 func (s *Store) MarkLatestChecked(site, seriesID string, ts int64) error {
 	if _, err := s.db.Exec(
@@ -966,7 +989,7 @@ func (s *Store) MarkLatestChecked(site, seriesID string, ts int64) error {
 }
 
 // LatestCheckedAt reads the column MarkLatestChecked writes. It exists for
-// tests outside this package (the poller's own tests assert on cooldown
+// tests outside this package (the poller's own tests assert on rest
 // bookkeeping) — see MarkLatestChecked for why the field stays off the
 // client-visible row.
 func (s *Store) LatestCheckedAt(site, seriesID string) (int64, error) {

backend/internal/store/store_test.go

@@ -298,7 +298,7 @@ func TestDueForLatestCheck(t *testing.T) {
 			s := newTestStore(t)
 			seedForCheck(t, s, "asura:x", tt.seriesURL, tt.checkedAt)
 
-			due, err := s.DueForLatestCheck(now-hour, now-hour, nil, 10)
+			due, err := s.DueForLatestCheck("asura", now-hour)
 			if err != nil {
 				t.Fatalf("DueForLatestCheck: %v", err)
 			}
@@ -309,22 +309,25 @@ func TestDueForLatestCheck(t *testing.T) {
 	}
 }
 
-func TestDueForLatestCheckOldestFirstAndLimited(t *testing.T) {
+func TestDueForLatestCheckOldestFirstAndScopedToSite(t *testing.T) {
 	s := newTestStore(t)
 	// Insert newest-checked first so a correct ORDER BY has to reverse it.
 	seedForCheck(t, s, "asura:c", "https://asurascans.com/comics/c", 300)
 	seedForCheck(t, s, "asura:b", "https://asurascans.com/comics/b", 200)
 	seedForCheck(t, s, "asura:a", "https://asurascans.com/comics/a", 100)
+	// A second Site's due series must not appear in asura's list: each Lane
+	// asks for one Site, and no Lane may see another's queue.
+	seedForCheck(t, s, "demonic:z", "https://demonicscans.org/manga/z", 0)
 
-	due, err := s.DueForLatestCheck(1000, 1000, nil, 2)
+	due, err := s.DueForLatestCheck("asura", 1000)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
-	if len(due) != 2 {
+	if len(due) != 3 {
-		t.Fatalf("got %d rows, want 2 (limit)", len(due))
+		t.Fatalf("got %d rows, want 3 (all of asura's, none of demonic's)", len(due))
 	}
-	if due[0].Key() != "asura:a" || due[1].Key() != "asura:b" {
+	if due[0].Key() != "asura:a" || due[1].Key() != "asura:b" || due[2].Key() != "asura:c" {
-		t.Fatalf("got %q,%q; want asura:a,asura:b (oldest first)", due[0].Key(), due[1].Key())
+		t.Fatalf("got %q,%q,%q; want asura:a,asura:b,asura:c (oldest first)", due[0].Key(), due[1].Key(), due[2].Key())
 	}
 }
 
@@ -496,7 +499,7 @@ func TestDueForLatestCheckSkipsFinishedKeepsArchived(t *testing.T) {
 		}
 	}
 
-	due, err := store.DueForLatestCheck(time.Now().UnixMilli(), time.Now().UnixMilli(), nil, 10)
+	due, err := store.DueForLatestCheck("asura", time.Now().UnixMilli())
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -512,6 +515,38 @@ func TestDueForLatestCheckSkipsFinishedKeepsArchived(t *testing.T) {
 	}
 }
 
+// The gap's denominator counts every Series the Lane will ever Poll: a
+// finished Series must not make the Lane faster than it needs to be, and
+// another Site's Series must not leak into this Site's count.
+func TestEligibleSeriesCount(t *testing.T) {
+	store := newTestStore(t)
+	seedForCheck(t, store, "asura:reading", "https://asurascans.com/comics/reading", 0)
+	seedForCheck(t, store, "asura:archived", "https://asurascans.com/comics/archived", 0)
+	if _, err := store.Upsert(store.OwnerID(), Bookmark{
+		Key: "asura:finished", Site: "asura", SeriesID: "finished",
+		SeriesURL: "https://asurascans.com/comics/finished",
+		Status:    StatusFinished, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed finished: %v", err)
+	}
+	seedForCheck(t, store, "demonic:z", "https://demonicscans.org/manga/z", 0)
+
+	n, err := store.EligibleSeriesCount("asura")
+	if err != nil {
+		t.Fatalf("EligibleSeriesCount: %v", err)
+	}
+	if n != 2 {
+		t.Fatalf("eligible = %d, want 2 (finished excluded, demonic excluded)", n)
+	}
+	n, err = store.EligibleSeriesCount("demonic")
+	if err != nil {
+		t.Fatalf("EligibleSeriesCount(demonic): %v", err)
+	}
+	if n != 1 {
+		t.Fatalf("eligible(demonic) = %d, want 1", n)
+	}
+}
+
 func TestDisplayChapter(t *testing.T) {
 	cases := []struct {
 		name string
@@ -970,7 +1005,7 @@ func TestDueForLatestCheckOrdersByReaderCountThenAge(t *testing.T) {
 	seedSecondReader(t, s, "asura:pop:2", "asura", "pop", 1001)
 	seedForCheck(t, s, "asura:solo", "https://asurascans.com/comics/solo", 100)
 
-	due, err := s.DueForLatestCheck(1000, 1000, nil, 10)
+	due, err := s.DueForLatestCheck("asura", 1000)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -996,7 +1031,7 @@ func TestDueForLatestCheckExcludesOrphanSeries(t *testing.T) {
 		t.Fatalf("seed orphan series: %v", err)
 	}
 
-	due, err := s.DueForLatestCheck(1000, 1000, nil, 10)
+	due, err := s.DueForLatestCheck("asura", 1000)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1334,7 +1369,7 @@ func TestTwoReadersShareOneSeriesWithIndependentProgress(t *testing.T) {
 		t.Fatalf("series rows = %d, want 1 shared row for two bookmarks", series)
 	}
 
-	due, err := s.DueForLatestCheck(time.Now().UnixMilli(), time.Now().UnixMilli(), nil, 10)
+	due, err := s.DueForLatestCheck("asura", time.Now().UnixMilli())
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1350,7 +1385,7 @@ func TestTwoReadersShareOneSeriesWithIndependentProgress(t *testing.T) {
 	if b, ok, err := s.Get(s.OwnerID(), "asura:solo"); err != nil || !ok || b.LastChapterNum != 200 {
 		t.Fatalf("owner's bookmark after the other's delete = %+v ok=%v err=%v, want it intact", b, ok, err)
 	}
-	due, err = s.DueForLatestCheck(time.Now().UnixMilli(), time.Now().UnixMilli(), nil, 10)
+	due, err = s.DueForLatestCheck("asura", time.Now().UnixMilli())
 	if err != nil {
 		t.Fatalf("DueForLatestCheck after delete: %v", err)
 	}

backend/main.go

@@ -7,7 +7,6 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
-	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -61,30 +60,15 @@ type Config struct {
 
 // LatestPoll configures the background latest-chapter poller.
 //
-// Sizing: batch x (cooldown / interval) is how many series hold a true cooldown
+// Only the kill switch lives here. Pace is per Site — rest time and gap are
-// cadence — 14 x (1h / 10m) = 84 with these defaults, which covers this
+// registry properties (internal/latest/sites.go, issue #100), because each
-// deployment. Past that nothing breaks; the effective cadence stretches to
+// Lane has to be able to differ from the others. The five environment
-// N x interval / batch and the oldest-checked-first ordering keeps it uniform.
+// settings that used to size a shared pace (cooldown, browser cooldown,
+// interval, stagger, batch) are gone with it: no deployed .env may carry them.
 type LatestPoll struct {
-	Enabled         bool
+	Enabled bool
-	Cooldown        time.Duration
-	BrowserCooldown time.Duration
-	Interval        time.Duration
-	Stagger         time.Duration
-	Batch           int
 }
 
-const (
-	defaultPollCooldown        = time.Hour
-	defaultBrowserPollCooldown = 6 * time.Hour
-	defaultPollInterval        = 10 * time.Minute
-	defaultPollStagger         = 20 * time.Second
-	defaultPollBatch           = 14
-	// minPollCooldown keeps a typo from turning a polite background check into
-	// a hammer against sites that are already bot-scoring us.
-	minPollCooldown = 15 * time.Minute
-)
-
 func envOr(key, def string) string {
 	if v := os.Getenv(key); v != "" {
 		return v
@@ -107,66 +91,11 @@ func envBool(key string, def bool) bool {
 	}
 }
 
-// envDuration reads a duration env var. An unparseable or non-positive value
+// loadLatestPoll reads the poller's settings. The pace knobs that used to be
-// falls back to def and logs rather than failing startup: the poller is an
+// clamped here are registry properties now (issue #100), so there is nothing
-// enhancement, and a typo in one of its knobs must not stop bookmark sync.
+// left to clamp.
-func envDuration(key string, def time.Duration) time.Duration {
-	raw := strings.TrimSpace(os.Getenv(key))
-	if raw == "" {
-		return def
-	}
-	d, err := time.ParseDuration(raw)
-	if err != nil || d <= 0 {
-		log.Printf("config: %s=%q is not a positive duration, using %s", key, raw, def)
-		return def
-	}
-	return d
-}
-
-// envInt reads a positive integer env var, with the same fallback policy.
-func envInt(key string, def int) int {
-	raw := strings.TrimSpace(os.Getenv(key))
-	if raw == "" {
-		return def
-	}
-	n, err := strconv.Atoi(raw)
-	if err != nil || n <= 0 {
-		log.Printf("config: %s=%q is not a positive integer, using %d", key, raw, def)
-		return def
-	}
-	return n
-}
-
-func clampPollCooldown(name string, d time.Duration) time.Duration {
-	if d < minPollCooldown {
-		log.Printf("config: %s %s is below the %s floor, clamping", name, d, minPollCooldown)
-		return minPollCooldown
-	}
-	return d
-}
-
-// loadLatestPoll reads the poller's settings, clamping anything that would make
-// it antisocial.
 func loadLatestPoll() LatestPoll {
-	p := LatestPoll{
+	return LatestPoll{Enabled: envBool("LATEST_CHAPTER_POLL_ENABLED", true)}
-		Enabled:         envBool("LATEST_CHAPTER_POLL_ENABLED", true),
-		Cooldown:        envDuration("LATEST_CHAPTER_POLL_COOLDOWN", defaultPollCooldown),
-		BrowserCooldown: envDuration("LATEST_CHAPTER_POLL_BROWSER_COOLDOWN", defaultBrowserPollCooldown),
-		Interval:        envDuration("LATEST_CHAPTER_POLL_INTERVAL", defaultPollInterval),
-		Stagger:         envDuration("LATEST_CHAPTER_POLL_STAGGER", defaultPollStagger),
-		Batch:           envInt("LATEST_CHAPTER_POLL_BATCH", defaultPollBatch),
-	}
-	p.Cooldown = clampPollCooldown("cooldown", p.Cooldown)
-	p.BrowserCooldown = clampPollCooldown("browser cooldown", p.BrowserCooldown)
-	// batch x stagger has to fit inside one tick or a batch is still running
-	// when the next one is due. Run() serialises them, so this degrades to a
-	// slower cadence rather than to overlapping fetches — worth a warning, not
-	// a failure.
-	if span := time.Duration(p.Batch) * p.Stagger; span > p.Interval {
-		log.Printf("config: batch(%d) x stagger(%s) = %s exceeds interval %s; batches will overrun their tick",
-			p.Batch, p.Stagger, span, p.Interval)
-	}
-	return p
 }
 
 func loadConfig() Config {
@@ -377,7 +306,8 @@ func main() {
 	}
 }
 
-// newLatestPoller wires the configured cooldowns and fetchers into the poller.
+// newLatestPoller wires the fetcher seams into the poller. Pace is registry
+// property, not config (issue #100), so there are no knobs to pass through.
 func newLatestPoller(s *store.Store, cfg LatestPoll, fetch, browser latest.Fetcher) *latest.Poller {
 	var covers latest.BrowserCoverFetcher
 	if f, ok := browser.(latest.BrowserCoverFetcher); ok {
@@ -390,11 +320,6 @@ func newLatestPoller(s *store.Store, cfg LatestPoll, fetch, browser latest.Fetch
 		CoverFetch:      covers,
 		CoverBytesFetch: latest.NewCoverFetcher(),
 		Now:             time.Now,
-		Cooldown:        cfg.Cooldown,
-		BrowserCooldown: cfg.BrowserCooldown,
-		Interval:        cfg.Interval,
-		Stagger:         cfg.Stagger,
-		Batch:           cfg.Batch,
 	}
 }
 

backend/main_test.go

@@ -9,31 +9,15 @@ import (
 	"net/http/httptest"
 	"strings"
 	"testing"
-	"time"
 
+	"bookmarkmanager/backend/internal/latest"
 	"bookmarkmanager/backend/internal/store"
 )
 
 func TestLoadLatestPollDefaults(t *testing.T) {
-	for _, k := range []string{
+	t.Setenv("LATEST_CHAPTER_POLL_ENABLED", "")
-		"LATEST_CHAPTER_POLL_ENABLED", "LATEST_CHAPTER_POLL_COOLDOWN",
+	if got := loadLatestPoll(); got != (LatestPoll{Enabled: true}) {
-		"LATEST_CHAPTER_POLL_BROWSER_COOLDOWN", "LATEST_CHAPTER_POLL_INTERVAL",
+		t.Fatalf("loadLatestPoll() = %+v, want %+v", got, LatestPoll{Enabled: true})
-		"LATEST_CHAPTER_POLL_STAGGER", "LATEST_CHAPTER_POLL_BATCH",
-	} {
-		t.Setenv(k, "")
-	}
-
-	got := loadLatestPoll()
-	want := LatestPoll{
-		Enabled:         true,
-		Cooldown:        time.Hour,
-		BrowserCooldown: 6 * time.Hour,
-		Interval:        10 * time.Minute,
-		Stagger:         20 * time.Second,
-		Batch:           14,
-	}
-	if got != want {
-		t.Fatalf("loadLatestPoll() = %+v, want %+v", got, want)
 	}
 }
 
@@ -63,105 +47,25 @@ func TestLoadLatestPollEnabledParsing(t *testing.T) {
 	}
 }
 
-func TestLoadLatestPollClampsAndFallsBack(t *testing.T) {
+// newLatestPoller wires the fetcher seams; pace lives in the registry, so
-	tests := []struct {
+// nothing here sizes a cooldown any more.
-		name     string
+func TestNewLatestPollerWiresFetchers(t *testing.T) {
-		env      map[string]string
+	tls := &latest.TLSFetcher{}
-		wantFrom func(LatestPoll) any
+	p := newLatestPoller(nil, LatestPoll{Enabled: true}, tls, nil)
-		want     any
+	if p.Fetch != tls {
-	}{
+		t.Fatalf("Fetch not wired")
-		{
-			name:     "cooldown below the floor is clamped up",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_COOLDOWN": "1m"},
-			wantFrom: func(p LatestPoll) any { return p.Cooldown },
-			want:     15 * time.Minute,
-		},
-		{
-			name:     "cooldown at the floor is kept",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_COOLDOWN": "15m"},
-			wantFrom: func(p LatestPoll) any { return p.Cooldown },
-			want:     15 * time.Minute,
-		},
-		{
-			name:     "browser cooldown below the floor is clamped up",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BROWSER_COOLDOWN": "1m"},
-			wantFrom: func(p LatestPoll) any { return p.BrowserCooldown },
-			want:     15 * time.Minute,
-		},
-		{
-			name:     "browser cooldown at the floor is kept",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BROWSER_COOLDOWN": "15m"},
-			wantFrom: func(p LatestPoll) any { return p.BrowserCooldown },
-			want:     15 * time.Minute,
-		},
-		{
-			name:     "browser cooldown override is honoured",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BROWSER_COOLDOWN": "8h"},
-			wantFrom: func(p LatestPoll) any { return p.BrowserCooldown },
-			want:     8 * time.Hour,
-		},
-		{
-			name:     "browser cooldown unparseable value falls back",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BROWSER_COOLDOWN": "six hours"},
-			wantFrom: func(p LatestPoll) any { return p.BrowserCooldown },
-			want:     6 * time.Hour,
-		},
-		{
-			name:     "a valid override is honoured",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_INTERVAL": "5m"},
-			wantFrom: func(p LatestPoll) any { return p.Interval },
-			want:     5 * time.Minute,
-		},
-		{
-			name:     "an unparseable duration falls back",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_INTERVAL": "ten minutes"},
-			wantFrom: func(p LatestPoll) any { return p.Interval },
-			want:     10 * time.Minute,
-		},
-		{
-			name:     "a zero duration falls back",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_STAGGER": "0s"},
-			wantFrom: func(p LatestPoll) any { return p.Stagger },
-			want:     20 * time.Second,
-		},
-		{
-			name:     "a valid batch is honoured",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BATCH": "30"},
-			wantFrom: func(p LatestPoll) any { return p.Batch },
-			want:     30,
-		},
-		{
-			name:     "a negative batch falls back",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BATCH": "-5"},
-			wantFrom: func(p LatestPoll) any { return p.Batch },
-			want:     14,
-		},
-		{
-			name:     "a non-numeric batch falls back",
-			env:      map[string]string{"LATEST_CHAPTER_POLL_BATCH": "lots"},
-			wantFrom: func(p LatestPoll) any { return p.Batch },
-			want:     14,
-		},
 	}
-	for _, tt := range tests {
+	if p.BrowserFetch != nil {
-		t.Run(tt.name, func(t *testing.T) {
+		t.Fatalf("BrowserFetch = %v, want nil for a browser-less deployment", p.BrowserFetch)
-			for k, v := range tt.env {
-				t.Setenv(k, v)
-			}
-			if got := tt.wantFrom(loadLatestPoll()); got != tt.want {
-				t.Fatalf("got %v, want %v", got, tt.want)
-			}
-		})
 	}
-}
+	if p.CoverFetch != nil {
-
+		t.Fatalf("CoverFetch = %v, want nil when the browser is absent", p.CoverFetch)
-func TestNewLatestPollerWiresCooldowns(t *testing.T) {
+	}
-	p := newLatestPoller(nil, LatestPoll{
+	if p.CoverBytesFetch == nil {
-		Cooldown:        time.Hour,
+		t.Fatalf("CoverBytesFetch = nil, want the TLS cover fetcher")
-		BrowserCooldown: 6 * time.Hour,
+	}
-	}, nil, nil)
+	if p.Now == nil {
-	if p.Cooldown != time.Hour || p.BrowserCooldown != 6*time.Hour {
+		t.Fatalf("Now = nil, want the live clock")
-		t.Fatalf("poller cooldowns = %s/%s, want 1h/6h", p.Cooldown, p.BrowserCooldown)
 	}
 }
 

docker-compose.yml

@@ -58,14 +58,11 @@ services:
       # Second script from the same bindmount; the novel library is a separate
       # Violentmonkey install.
       NOVEL_USERSCRIPT_PATH: ${NOVEL_USERSCRIPT_PATH:-/userscript/novel-bookmark.user.js}
-      # Latest-chapter poller. LATEST_CHAPTER_POLL_ENABLED=0 in .env is the kill
+      # Latest-chapter poller. LATEST_CHAPTER_POLL_ENABLED=0 in .env is the
-      # switch; it only takes effect because these are listed here.
+      # kill switch; it only takes effect because it is listed here. Pace is
+      # per Site in the registry (one Poll Lane per Site, issue #100) — the
+      # cooldown/interval/stagger/batch knobs are gone with the shared pace.
       LATEST_CHAPTER_POLL_ENABLED: ${LATEST_CHAPTER_POLL_ENABLED:-1}
-      LATEST_CHAPTER_POLL_COOLDOWN: ${LATEST_CHAPTER_POLL_COOLDOWN:-1h}
-      LATEST_CHAPTER_POLL_BROWSER_COOLDOWN: ${LATEST_CHAPTER_POLL_BROWSER_COOLDOWN:-6h}
-      LATEST_CHAPTER_POLL_INTERVAL: ${LATEST_CHAPTER_POLL_INTERVAL:-10m}
-      LATEST_CHAPTER_POLL_BATCH: ${LATEST_CHAPTER_POLL_BATCH:-14}
-      LATEST_CHAPTER_POLL_STAGGER: ${LATEST_CHAPTER_POLL_STAGGER:-20s}
       # CDP endpoint for sites behind a JavaScript challenge (kagane,
       # novelfull). The browser is not part of this stack — it runs on the home
       # machine as its own unit (chrome/docker-compose.yml) and is reached over

docs/adr/0010-poll-lanes-per-site-pace.md

@@ -0,0 +1,91 @@
+# ADR-0010: Poll Lanes — one independent Poll stream per Site
+
+Date: 2026-08-16
+Status: accepted
+
+## Decision
+
+Replace the single shared polling pace with one **Poll Lane** per Site: an
+independent goroutine that polls only that Site's Series, paced by that Site's
+registry entry. Pace moves out of config and into the Site registry
+(`internal/latest/sites.go`): every entry carries a `Rest` (how long a Series
+rests between Polls) and a `Gap` (how long the Lane waits between fetches).
+
+Rest is enforced by the due query's WHERE clause (`latest_checked_at <= now -
+Rest`), never by a timer — the same mechanism that enforced the old cooldown.
+The Lane enforces its own gap by sleeping between fetches. `effectiveGap` is
+the registry gap, or one hour divided by the Site's eligible Series count when
+that is smaller, never below one second.
+
+The five environment settings that used to size the shared pace —
+`LATEST_CHAPTER_POLL_COOLDOWN`, `_BROWSER_COOLDOWN`, `_INTERVAL`, `_BATCH`,
+`_STAGGER` — are deleted. Only the kill switch `LATEST_CHAPTER_POLL_ENABLED`
+remains. No deployed `.env` may carry the deleted knobs.
+
+## Why
+
+The shared pace capped the whole backend at roughly 180 Polls an hour (one
+20-second stagger across one queue). ~60 Series today, scaling to hundreds or
+thousands, would stretch the hour beyond what the New Chapter signal can
+tolerate. Worse, the queue mixed Sites with very different costs: kagane and
+comix pay seconds of a serialized single-tab Chrome per Poll (a challenged
+page, ADR-0005), and one hostile Site burning its challenge timeout made every
+other Site's Series wait — "one hostile Site can eat most of an hour".
+
+Lanes fix both at once:
+
+- **Throughput scales per Site.** The six Lanes fetch concurrently; a Lane's
+  own gap paces it. The browser Lanes' combined ceiling stays about 360 Polls
+  an hour (one tab), and when they cannot keep up the wait past Rest grows and
+  is logged every pass — the "behind by X" measurement, so the decision to
+  give browser Sites more pages is made from data.
+- **Hostility is contained.** A refusal (two challenge-held reads in one
+  pass) stops only that Site's Lane for `refuseBackoff` (15m); the rest of
+  that Lane's Series stay unstamped and due. A lost browser gates the other
+  browser Lanes' passes for the same window — the flag is shared Poller
+  state, so the loss is noticed once instead of once per Lane per pass, and
+  decays after 15m so the Lanes probe again. One Site can no longer tax the
+  others.
+
+## Tradeoffs and rejections
+
+- **Per-Site env knobs** (e.g. `KAGANE_POLL_GAP`) rejected: the registry is
+  the single place pace lives, testable and reviewable; config knobs would
+  recreate the shared-pace sprawl with six times the surface. All six entries
+  are deliberately uniform at first — rest an hour, gap ten seconds — so the
+  structure exists to differ without inventing numbers for Sites that have
+  not earned them.
+- **Dynamic gap** (`rest / eligible`) is the one knob that stays automatic:
+  a Site with more Series than one per ten seconds would otherwise back up
+  behind its own gap, and the per-Series share of the hour is the natural
+  pace. The ten-second default is not arbitrary: one request per ten seconds
+  is the strictest rate rule a free-plan Site can even express (per-zone
+  rate limiting, as documented in
+  `docs/research/cloudflare-bot-scoring-and-poll-cadence.md`), so the
+  default pace is exactly what the most restrictive Site would demand of us.
+  The computed gap never goes below one second and logs loudly when the
+  floor engages.
+- **Timer-based pacing** rejected: the old ticker made the poller's rate a
+  function of wall clock rather than of what was due. The due-query cutoff is
+  the only rate authority; the Lane sleep just prevents hammering.
+- **Batch size** (the old `_BATCH` cap) is gone with the shared pace: a Lane
+  processes everything due, paced by its gap. There is no global queue left
+  to bound.
+
+## Constraints preserved
+
+- Stamp-before-fetch ("attempted" semantics): an untried Series stays due, so
+  a browser that appears after a restart finds its full queue waiting.
+- Browser wake gate (ADR-0005): a browser Lane leaves Chrome asleep below
+  five due Series and 15 minutes of wait, per Lane.
+- The browser is not in the API stack (ADR-0006): an unreachable browser
+  degrades a Lane exactly as an unset `BROWSER_WS_URL` — browser-only Sites
+  skipped, plain-TLS unaffected, stored covers still served.
+- Cover heals moved to background goroutines (joined by the test suite via
+  `waitCovers`) so a slow cover CDN cannot consume a Lane's gap.
+
+Supersedes the pace mechanics of ADR-0003's "raise throughput instead" note
+(the stagger cut it rejected is what the per-Lane gap replaces) and the
+6-hour browser cooldown introduced with the browser-backed Sites; the
+1-hour browser rest was already cleared as safe by
+`docs/research/cloudflare-bot-scoring-and-poll-cadence.md`.

graphify-out/.graphify_labels.json

@@ -30,7 +30,8 @@
   "28": "Allocation Patterns",
   "29": "Observability & Alerting",
   "30": "AGENTS.md",
-  "32": "Repo Hard Constraints",
+  "31": "Store",
+  "32": "Open",
   "33": "Go Testing Guide",
   "34": "Session Store",
   "35": "Web UI Filter Logic",
@@ -39,7 +40,7 @@
   "38": "novel-logic.test.js",
   "39": "UI Critique 2026-07-26A",
   "40": "UI Critique 2026-07-26B",
-  "41": "sessions_test.go",
+  "42": "pgtest.go",
   "43": "Issue Tracker & Triage",
   "44": "Ticket Workflow",
   "45": "Go Perf Alert Rules",
@@ -122,6 +123,7 @@
   "122": "Identity comes from Discord OAuth; we store no passwords and send no email",
   "123": "The wire format stays flat and deliberately does not mirror the schema",
   "124": "ADR-0005: On-demand browser sidecar",
+  "125": "sessions_test.go",
   "126": "Bookmark Manager",
   "127": "triage-labels.md",
   "128": "Cross-Ticket Contract",
@@ -149,7 +151,6 @@
   "150": "Reviewer Subagent (opencode)",
   "151": "Finding Severity Rubric",
   "152": "Spec Compliance Review",
-  "158": "T",
   "161": "Why Use samber/oops",
   "162": "singleflight Cache Stampede Prevention",
   "163": "Struct Field Alignment",

graphify-out/GRAPH_REPORT.md

@@ -1,16 +1,16 @@
 # Graph Report - mangaBookmark  (2026-08-16)
 
 ## Corpus Check
-- 112 files · ~274,851 words
+- 113 files · ~279,161 words
 - Verdict: corpus is large enough that graph structure adds value.
 
 ## Summary
-- 1640 nodes · 3294 edges · 221 communities (67 shown, 154 thin omitted)
+- 1668 nodes · 3379 edges · 222 communities (68 shown, 154 thin omitted)
-- Extraction: 90% EXTRACTED · 10% INFERRED · 0% AMBIGUOUS · INFERRED: 313 edges (avg confidence: 0.77)
+- Extraction: 91% EXTRACTED · 9% INFERRED · 0% AMBIGUOUS · INFERRED: 320 edges (avg confidence: 0.77)
 - Token cost: 0 input · 0 output
 
 ## Graph Freshness
-- Built from commit: `f000cc7e`
+- Built from commit: `4f1cbcfd`
 - Run `git rev-parse HEAD` and compare to check if the graph is stale.
 - Run `graphify update .` after code changes (no API cost).
 
@@ -45,7 +45,8 @@
 - [[_COMMUNITY_Find Skills Guide|Find Skills Guide]]
 - [[_COMMUNITY_Allocation Patterns|Allocation Patterns]]
 - [[_COMMUNITY_Observability & Alerting|Observability & Alerting]]
-- [[_COMMUNITY_Repo Hard Constraints|Repo Hard Constraints]]
+- [[_COMMUNITY_Store|Store]]
+- [[_COMMUNITY_Open|Open]]
 - [[_COMMUNITY_Go Testing Guide|Go Testing Guide]]
 - [[_COMMUNITY_Session Store|Session Store]]
 - [[_COMMUNITY_Web UI Filter Logic|Web UI Filter Logic]]
@@ -54,7 +55,7 @@
 - [[_COMMUNITY_novel-logic.test.js|novel-logic.test.js]]
 - [[_COMMUNITY_UI Critique 2026-07-26A|UI Critique 2026-07-26A]]
 - [[_COMMUNITY_UI Critique 2026-07-26B|UI Critique 2026-07-26B]]
-- [[_COMMUNITY_sessions_test.go|sessions_test.go]]
+- [[_COMMUNITY_pgtest.go|pgtest.go]]
 - [[_COMMUNITY_Issue Tracker & Triage|Issue Tracker & Triage]]
 - [[_COMMUNITY_Ticket Workflow|Ticket Workflow]]
 - [[_COMMUNITY_Go Perf Alert Rules|Go Perf Alert Rules]]
@@ -137,6 +138,7 @@
 - [[_COMMUNITY_Identity comes from Discord OAuth; we store no passwords and send no email|Identity comes from Discord OAuth; we store no passwords and send no email]]
 - [[_COMMUNITY_The wire format stays flat and deliberately does not mirror the schema|The wire format stays flat and deliberately does not mirror the schema]]
 - [[_COMMUNITY_ADR-0005 On-demand browser sidecar|ADR-0005: On-demand browser sidecar]]
+- [[_COMMUNITY_sessions_test.go|sessions_test.go]]
 - [[_COMMUNITY_Bookmark Manager|Bookmark Manager]]
 - [[_COMMUNITY_triage-labels|triage-labels.md]]
 - [[_COMMUNITY_Cross-Ticket Contract|Cross-Ticket Contract]]
@@ -164,7 +166,6 @@
 - [[_COMMUNITY_Reviewer Subagent (opencode)|Reviewer Subagent (opencode)]]
 - [[_COMMUNITY_Finding Severity Rubric|Finding Severity Rubric]]
 - [[_COMMUNITY_Spec Compliance Review|Spec Compliance Review]]
-- [[_COMMUNITY_T|T]]
 - [[_COMMUNITY_Why Use samberoops|Why Use samber/oops]]
 - [[_COMMUNITY_singleflight Cache Stampede Prevention|singleflight Cache Stampede Prevention]]
 - [[_COMMUNITY_Struct Field Alignment|Struct Field Alignment]]
@@ -239,14 +240,14 @@
 ## God Nodes (most connected - your core abstractions)
 1. `testConfig()` - 53 edges
 2. `newWebTestServer()` - 49 edges
-3. `newTestStore()` - 43 edges
+3. `newTestStore()` - 48 edges
-4. `newTestStore()` - 42 edges
+4. `newTestStore()` - 43 edges
 5. `e()` - 33 edges
-6. `Handler` - 29 edges
+6. `Open()` - 29 edges
-7. `ne()` - 28 edges
+7. `Handler` - 29 edges
-8. `De()` - 28 edges
+8. `ne()` - 28 edges
-9. `Open()` - 27 edges
+9. `De()` - 28 edges
-10. `se()` - 27 edges
+10. `Store` - 27 edges
 
 ## Surprising Connections (you probably didn't know these)
 - `el()` --indirect_call--> `c()`  [INFERRED]
@@ -272,7 +273,7 @@
 - **Headless browser infrastructure (sidecar, on-demand, home deployment)** — docs_adr_0005_on_demand_browser_headless_shell, docs_adr_0005_on_demand_browser_cdp, docs_adr_0005_on_demand_browser_on_demand_start, docs_adr_0006_browser_on_the_home_machine_home_machine_rationale [INFERRED 0.85]
 - **lightnovelworld series-identity investigation and fix** — docs_research_lightnovelworld_chapter_vs_series_slug_issue_77, docs_research_lightnovelworld_chapter_vs_series_slug_unscoped_regex, docs_adr_0008_series_identity_is_discovered_not_derived_discovered_identity [INFERRED 0.85]
 
-## Communities (221 total, 154 thin omitted)
+## Communities (222 total, 154 thin omitted)
 
 ### Community 0 - "HTMX Library Internals"
 Cohesion: 0.08
@@ -284,30 +285,30 @@ Nodes (84): floatPtr(), testConfig(), getCover(), Cookie, Handler, ResponseRecor
 
 ### Community 2 - "Manga Userscript Adapters"
 Cohesion: 0.06
-Nodes (77): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+69 more)
+Nodes (76): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+68 more)
 
 ### Community 3 - "Novel Userscript Adapters"
 Cohesion: 0.06
-Nodes (78): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+70 more)
+Nodes (79): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+71 more)
 
 ### Community 4 - "Series Acquisition Tests"
-Cohesion: 0.09
+Cohesion: 0.08
-Nodes (69): bookmarkNewKaganeSeries(), bookmarkNewNovelfullSeries(), bookmarkNewSeries(), Context, Store, T, newAcquirer(), readBookmark() (+61 more)
+Nodes (78): bookmarkNewKaganeSeries(), bookmarkNewNovelfullSeries(), bookmarkNewSeries(), Context, Store, T, newAcquirer(), readBookmark() (+70 more)
 
 ### Community 5 - "Bookmarks API Tests"
-Cohesion: 0.08
+Cohesion: 0.06
-Nodes (67): auth(), getBookmarks(), Handler, Request, Store, T, newTestServer(), newTestStore() (+59 more)
+Nodes (74): auth(), getBookmarks(), Handler, Request, Store, T, newTestServer(), newTestStore() (+66 more)
 
 ### Community 7 - "Cover & Acquire Internals"
-Cohesion: 0.10
+Cohesion: 0.08
-Nodes (30): Addr, Context, Store, defaultCoverResolver(), fetchCoverBytes(), Client, Context, NewCoverFetcher() (+22 more)
+Nodes (37): Addr, Context, Store, WaitGroup, isInterstitial(), defaultCoverResolver(), fetchCoverBytes(), Client (+29 more)
 
 ### Community 8 - "System Architecture Concepts"
 Cohesion: 0.13
 Nodes (20): app.html — App Shell Template, Manga/Novel Library Switch, Bookmark Bucket Tabs, Confirm Row (Archive/Finish/Remove), card.html — Series Card Template, htmx /ui/* Mutation Endpoints, chrome.html — Out-of-Band Regions, Action Key (+12 more)
 
 ### Community 9 - "Session Middleware"
-Cohesion: 0.07
+Cohesion: 0.08
 Nodes (35): ClearCookie(), ClientIP(), Duration, Mutex, Request, ResponseWriter, Time, isHTTPS() (+27 more)
 
 ### Community 10 - "Go Test Helpers"
@@ -315,12 +316,12 @@ Cohesion: 0.05
 Nodes (39): Test Helpers, Test Timeout, Basic Handler Test, HTTP Handler Testing, Query Parameters and Headers, Docker Compose Fixture, Integration Testing, SQL Schema Fixture (+31 more)
 
 ### Community 11 - "Store Tests"
-Cohesion: 0.15
+Cohesion: 0.14
-Nodes (43): Store, T, newTestStore(), readLatestCheckedAt(), readSeries(), secondReader(), seedForCheck(), seedSecondReader() (+35 more)
+Nodes (45): scanSeries(), Store, T, newTestStore(), readLatestCheckedAt(), readSeries(), secondReader(), seedForCheck() (+37 more)
 
 ### Community 12 - "Bookmarks API Handler"
-Cohesion: 0.11
+Cohesion: 0.08
-Nodes (24): Auth(), compressible(), CORS(), Handler, ResponseWriter, Store, Gzip(), ResolveReader() (+16 more)
+Nodes (32): Handler, Request, ResponseWriter, Store, Healthz(), writeJSON(), Auth(), compressible() (+24 more)
 
 ### Community 13 - "Web UI Handlers"
 Cohesion: 0.14
@@ -331,8 +332,8 @@ Cohesion: 0.06
 Nodes (33): Creating Errors, Custom Error Types, Custom types that wrap other errors, Decision table: which error strategy to use, Error Creation, Error String Conventions, Errors as Values, `errors.New` — static error messages (+25 more)
 
 ### Community 15 - "CDP Browser Client"
-Cohesion: 0.07
+Cohesion: 0.06
-Nodes (36): awaitPromise(), browserConnectionLost(), classifyBrowserError(), comixRead(), comixSeriesPageURL(), Action, Context, Mutex (+28 more)
+Nodes (56): awaitPromise(), browserConnectionLost(), classifyBrowserError(), comixRead(), comixSeriesPageURL(), Action, Context, Mutex (+48 more)
 
 ### Community 16 - "Cloudflare bot scoring and poll cadence — what is actually documented"
 Cohesion: 0.06
@@ -343,8 +344,8 @@ Cohesion: 0.08
 Nodes (23): Code Style Details, Extract Complex Conditions, Value vs Pointer Arguments, Code Organization Within Files, Complex Conditions & Init Scope, Composite Literals, Control Flow, Cross-References (+15 more)
 
 ### Community 19 - "Store"
-Cohesion: 0.09
+Cohesion: 0.33
-Nodes (8): coverRelativePath(), coverSourceAddress(), displayChapter(), Store, scanSeries(), TestDisplayChapter(), Bookmark, ReaderSummary
+Nodes (5): ADR-0010: Poll Lanes — one independent Poll stream per Site, Constraints preserved, Decision, Tradeoffs and rejections, Why
 
 ### Community 20 - "I/O Performance Patterns"
 Cohesion: 0.11
@@ -371,24 +372,28 @@ Cohesion: 0.33
 Nodes (12): coverResponse(), Request, T, TestCoverFetcherCanonicalisesJpgAlias(), TestCoverFetcherFetchesPublicHTTPSImage(), TestCoverFetcherRefusesUnsafeDestinationsBeforeRequest(), TestCoverFetcherRejectsNonImage(), TestCoverFetcherRejectsOversizedBody() (+4 more)
 
 ### Community 26 - "Open"
-Cohesion: 0.20
+Cohesion: 0.40
-Nodes (17): applyMigration(), migrate(), Open(), refreshOwnerToken(), seedOwner(), TestCoverIsContentAddressedOnFilesystem(), TestCoverPersistsAcrossReopen(), TestMigration0002BackfillsExistingBookmarks() (+9 more)
+Nodes (5): Map of pointers for large, frequently updated structs, Memory Layout, Pointer receivers for large structs, Struct field alignment, Zero-size field at end of struct
 
 ### Community 27 - "Find Skills Guide"
 Cohesion: 0.14
 Nodes (13): Common Skill Categories, Find Skills, How to Help Users Find Skills, Step 1: Understand What They Need, Step 2: Check the Leaderboard First, Step 3: Search for Skills, Step 4: Verify Quality Before Recommending, Step 5: Present Options to the User (+5 more)
 
 ### Community 28 - "Allocation Patterns"
-Cohesion: 0.11
+Cohesion: 0.14
-Nodes (19): Allocation Patterns, Backing Array Leaks, Direct indexing vs append, Eliminate redundant map lookups, Interface boxing, Map never shrinks, Map of pointers for large, frequently updated structs, Map size hints (+11 more)
+Nodes (14): Allocation Patterns, Backing Array Leaks, Direct indexing vs append, Eliminate redundant map lookups, Interface boxing, Map never shrinks, Map size hints, Memory Optimization (+6 more)
 
 ### Community 29 - "Observability & Alerting"
 Cohesion: 0.22
 Nodes (9): Alerting rules (examples), CPU saturation, GC pressure, Goroutine leaks, Grafana Dashboards, Memory leaks, Prometheus Metrics for Go, PromQL Queries for Performance Diagnosis (+1 more)
 
-### Community 32 - "Repo Hard Constraints"
+### Community 31 - "Store"
-Cohesion: 0.18
+Cohesion: 0.12
-Nodes (12): M, TestMain(), M, TestMain(), M, Main(), start(), URL() (+4 more)
+Nodes (3): coverRelativePath(), coverSourceAddress(), Store
+
+### Community 32 - "Open"
+Cohesion: 0.14
+Nodes (20): applyMigration(), displayChapter(), migrate(), Open(), refreshOwnerToken(), seedOwner(), TestCoverIsContentAddressedOnFilesystem(), TestCoverPersistsAcrossReopen() (+12 more)
 
 ### Community 33 - "Go Testing Guide"
 Cohesion: 0.20
@@ -418,9 +423,9 @@ Nodes (6): Design Health Score, Design Specificity Verdict, Minor Observations,
 Cohesion: 0.29
 Nodes (6): Design Health Score, Design Specificity Verdict, Minor Observations, Persona Red Flags, Priority Issues, Questions to Consider
 
-### Community 41 - "sessions_test.go"
+### Community 42 - "pgtest.go"
-Cohesion: 0.48
+Cohesion: 0.18
-Nodes (6): T, TestCreateAndGetSession(), TestDeleteSessionIsPerReader(), TestDeleteSessionRevokes(), TestExpiredSessionIsGone(), TestGetSessionUnknownID()
+Nodes (12): M, TestMain(), M, TestMain(), M, Main(), start(), URL() (+4 more)
 
 ### Community 45 - "Go Perf Alert Rules"
 Cohesion: 0.50
@@ -530,28 +535,28 @@ Nodes (3): Consequence, The wire format stays flat and deliberately does not mir
 Cohesion: 0.50
 Nodes (3): ADR-0005: On-demand browser sidecar, Constraints, Decision
 
-### Community 158 - "T"
+### Community 125 - "sessions_test.go"
-Cohesion: 0.08
+Cohesion: 0.48
-Nodes (38): Handler, Request, ResponseWriter, Store, Healthz(), writeJSON(), Request, ReaderID() (+30 more)
+Nodes (6): T, TestCreateAndGetSession(), TestDeleteSessionIsPerReader(), TestDeleteSessionRevokes(), TestExpiredSessionIsGone(), TestGetSessionUnknownID()
 
 ### Community 273 - "AGENTS.md"
 Cohesion: 0.50
 Nodes (3): Live URL shapes (verified 2026-07-26, may drift — re-check against live pages before trust), Second script: `novel-bookmark.user.js`, Userscript structure (single IIFE, `manga-bookmark.user.js`)
 
 ## Knowledge Gaps
-- **520 isolated node(s):** `bookmarkmanager/backend`, `ctxKey`, `loginView`, `ctxKey`, `test` (+515 more)
+- **524 isolated node(s):** `bookmarkmanager/backend`, `ctxKey`, `loginView`, `ctxKey`, `test` (+519 more)
   These have ≤1 connection - possible missing edges or undocumented components.
 - **154 thin communities (<3 nodes) omitted from report** — run `graphify query` to explore isolated nodes.
 
 ## Suggested Questions
 _Questions this graph is uniquely positioned to answer:_
 
-- **Why does `New()` connect `Series Acquisition Tests` to `Bookmarks API Tests`, `Cover & Acquire Internals`, `Session Middleware`, `Web UI Handlers`, `Open`?**
+- **Why does `New()` connect `Series Acquisition Tests` to `Open`, `Bookmarks API Tests`, `Cover & Acquire Internals`, `Session Middleware`, `Web UI Handlers`?**
-  _High betweenness centrality (0.051) - this node is a cross-community bridge._
+  _High betweenness centrality (0.045) - this node is a cross-community bridge._
-- **Why does `Open()` connect `Open` to `Repo Hard Constraints`, `Cover Fetch Test Helpers`, `Series Acquisition Tests`, `Bookmarks API Tests`, `Store Tests`, `Store`?**
+- **Why does `Open()` connect `Open` to `Cover Fetch Test Helpers`, `Series Acquisition Tests`, `Bookmarks API Tests`, `pgtest.go`, `Store Tests`, `Store`?**
-  _High betweenness centrality (0.038) - this node is a cross-community bridge._
+  _High betweenness centrality (0.033) - this node is a cross-community bridge._
 - **Why does `newRouter()` connect `Bookmarks API Tests` to `Cover Fetch Test Helpers`, `Bookmarks API Handler`, `Series Acquisition Tests`?**
-  _High betweenness centrality (0.030) - this node is a cross-community bridge._
+  _High betweenness centrality (0.027) - this node is a cross-community bridge._
 - **Are the 47 inferred relationships involving `testConfig()` (e.g. with `TestListRendersAcquiredCover()` and `TestPublicCoverNeverEchoesNonImage()`) actually correct?**
   _`testConfig()` has 47 INFERRED edges - model-reasoned connections that need verification._
 - **Are the 8 inferred relationships involving `newWebTestServer()` (e.g. with `TestListRendersAcquiredCover()` and `TestPublicCoverRejectsUnknownAddress()`) actually correct?**
@@ -559,4 +564,4 @@ _Questions this graph is uniquely positioned to answer:_
 - **Are the 12 inferred relationships involving `newTestStore()` (e.g. with `TestAcquireDoesNotBlockTheWrite()` and `TestAcquireFailureLeavesTheBookmarkIntact()`) actually correct?**
   _`newTestStore()` has 12 INFERRED edges - model-reasoned connections that need verification._
 - **What connects `bookmarkmanager/backend`, `ctxKey`, `loginView` to the rest of the system?**
-  _553 weakly-connected nodes found - possible documentation gaps or missing edges._
+  _557 weakly-connected nodes found - possible documentation gaps or missing edges._

graphify-out/manifest.json

@@ -25,9 +25,9 @@
     "semantic_hash": "dac242903b0e98c3e4395159d609e08e"
   },
   "backend/main.go": {
-    "mtime": 1786501521.228955,
+    "mtime": 1786859325.126449,
-    "ast_hash": "6e98a3ae91aaa132df251e43c4dfca6d",
+    "ast_hash": "4ad77c286522f97d14b6009ff37118e5",
-    "semantic_hash": "6e98a3ae91aaa132df251e43c4dfca6d"
+    "semantic_hash": ""
   },
   "skills-lock.json": {
     "mtime": 1784884678.6842625,
@@ -140,18 +140,18 @@
     "semantic_hash": "3a08979e4603aae5c32a58d5b6c39765"
   },
   "CLAUDE.md": {
-    "mtime": 1786856633.445473,
+    "mtime": 1786857336.6414917,
-    "ast_hash": "fab288c23be960d9c6afbfe3f21ff41c",
+    "ast_hash": "c79e49f912d7852f9832565a5f9a1c39",
     "semantic_hash": ""
   },
   "DEPLOY.md": {
-    "mtime": 1786501942.7367291,
+    "mtime": 1786859620.9977603,
-    "ast_hash": "3c7b785c44badb6dda6234d2b39a9290",
+    "ast_hash": "b7c2f813aded562ee9291c9baed795ad",
     "semantic_hash": ""
   },
   "README.md": {
-    "mtime": 1786499529.7651505,
+    "mtime": 1786859273.3238454,
-    "ast_hash": "9d6be8aa8a2946c23ad48d8f2864b5ca",
+    "ast_hash": "81af12a0a2d43e791efd030b5f4d6cbc",
     "semantic_hash": ""
   },
   "docker-compose.prod.yml": {
@@ -160,8 +160,8 @@
     "semantic_hash": "0751998a532297b8ac507a01ec48dc31"
   },
   "docker-compose.yml": {
-    "mtime": 1786499529.7725692,
+    "mtime": 1786859258.6255276,
-    "ast_hash": "124fd581bf0a662ff15012abfdb40a92",
+    "ast_hash": "d3b53a8f42a8e0acb4fc4306ea42c093",
     "semantic_hash": ""
   },
   ".claude/settings.json": {
@@ -175,9 +175,9 @@
     "semantic_hash": "8f1b093b59eb1ed81bc7fc0c22495c50"
   },
   "backend/main_test.go": {
-    "mtime": 1786501521.228955,
+    "mtime": 1786859172.6449091,
-    "ast_hash": "8a165955cf28ad47481fec5ea7afb3d6",
+    "ast_hash": "0a5d4dbdc770b40c329ccccc899b59f4",
-    "semantic_hash": "8a165955cf28ad47481fec5ea7afb3d6"
+    "semantic_hash": ""
   },
   ".claude/settings.local.json": {
     "mtime": 1785697645.350201,
@@ -200,8 +200,8 @@
     "semantic_hash": "e69a8340a371579ca3ea689660f7d7bd"
   },
   "AGENTS.md": {
-    "mtime": 1786856633.445473,
+    "mtime": 1786857336.6414917,
-    "ast_hash": "fab288c23be960d9c6afbfe3f21ff41c",
+    "ast_hash": "c79e49f912d7852f9832565a5f9a1c39",
     "semantic_hash": ""
   },
   "userscript/test/logic.test.js": {
@@ -215,7 +215,7 @@
     "semantic_hash": "8f3c0132eb4787a2c8736eb99f7689af"
   },
   "REDEPLOY.md": {
-    "mtime": 1786856643.0770833,
+    "mtime": 1786857336.6414917,
     "ast_hash": "e5e910f0244a040e2ccdc669b17eb4db",
     "semantic_hash": ""
   },
@@ -245,12 +245,12 @@
     "semantic_hash": "385b36f58488b7e6d93eb6d6034e9ee3"
   },
   "backend/internal/latest/browser.go": {
-    "mtime": 1786856879.3397639,
+    "mtime": 1786859355.8677974,
-    "ast_hash": "fbdba4bb56d8c804087bcb6e141e52ad",
+    "ast_hash": "75f34a974568d122681939dd297944a2",
     "semantic_hash": ""
   },
   "backend/internal/latest/browser_test.go": {
-    "mtime": 1786856254.36163,
+    "mtime": 1786857336.6414917,
     "ast_hash": "800fa6aa471ada054a3c48943ad17ab7",
     "semantic_hash": ""
   },
@@ -260,22 +260,22 @@
     "semantic_hash": ""
   },
   "backend/internal/latest/poller.go": {
-    "mtime": 1786856670.129715,
+    "mtime": 1786860083.6713927,
-    "ast_hash": "6b7060ff52994729832d9fcc3cc97dad",
+    "ast_hash": "be728405cde3df49baf72bd7837f2971",
     "semantic_hash": ""
   },
   "backend/internal/latest/poller_test.go": {
-    "mtime": 1786856311.8535168,
+    "mtime": 1786860168.103984,
-    "ast_hash": "b6837fab377c94fa1d2f20a931975a4a",
+    "ast_hash": "5dba515d28c0523500c1ceb581a54e58",
     "semantic_hash": ""
   },
   "backend/internal/latest/sites.go": {
-    "mtime": 1786856865.4529688,
+    "mtime": 1786860007.8224697,
-    "ast_hash": "2f00456ac9d1d8148ba1bc6cbceb24f6",
+    "ast_hash": "9b90f9b710ccbd0d0a0a6a0dd721ff3c",
     "semantic_hash": ""
   },
   "backend/internal/latest/sites_test.go": {
-    "mtime": 1786856890.1231265,
+    "mtime": 1786857336.6414917,
     "ast_hash": "0db2028a6073f342fee61ad15c2e5f0f",
     "semantic_hash": ""
   },
@@ -340,14 +340,14 @@
     "semantic_hash": "0b6764a0ee20f5cb7748eecd31a1d220"
   },
   "backend/internal/store/store.go": {
-    "mtime": 1786363889.5602942,
+    "mtime": 1786860012.3431706,
-    "ast_hash": "54367a8ab043983e2491b2eb2650961c",
+    "ast_hash": "c62e73142386c58ab833d404d0c24dc4",
-    "semantic_hash": "54367a8ab043983e2491b2eb2650961c"
+    "semantic_hash": ""
   },
   "backend/internal/store/store_test.go": {
-    "mtime": 1786363889.5602942,
+    "mtime": 1786858248.9426548,
-    "ast_hash": "dc823fd77bcce2268114e31d759b20a5",
+    "ast_hash": "039729554517960d1ae98f8409baf4ba",
-    "semantic_hash": "dc823fd77bcce2268114e31d759b20a5"
+    "semantic_hash": ""
   },
   "backend/internal/userscript/userscript.go": {
     "mtime": 1786216141.692644,
@@ -415,8 +415,8 @@
     "semantic_hash": "e44a2f6f624db044e19508bc5ab05592"
   },
   "CONTEXT.md": {
-    "mtime": 1786855457.9327722,
+    "mtime": 1786859395.4497814,
-    "ast_hash": "24548f60414b4c5ff58538acaada5345",
+    "ast_hash": "4aafbce0b046e6e34734fb414df818ce",
     "semantic_hash": ""
   },
   "CUTOVER.md": {
@@ -425,13 +425,13 @@
     "semantic_hash": "6c6f3e4c4c2f57867894280bce728c50"
   },
   "backend/AGENTS.md": {
-    "mtime": 1786856656.6826186,
+    "mtime": 1786860230.7890837,
-    "ast_hash": "d5610ba24076b57e17b9d76241acaa65",
+    "ast_hash": "7ceec7c4576f6e91eaf02c200a0dd1b3",
     "semantic_hash": ""
   },
   "backend/CLAUDE.md": {
-    "mtime": 1786856656.6826186,
+    "mtime": 1786860230.7890837,
-    "ast_hash": "d5610ba24076b57e17b9d76241acaa65",
+    "ast_hash": "7ceec7c4576f6e91eaf02c200a0dd1b3",
     "semantic_hash": ""
   },
   "backend/internal/web/templates/app.html": {
@@ -560,7 +560,7 @@
     "semantic_hash": "46cf7822d4f667e3cab36b547abe5e97"
   },
   "backend/internal/latest/cover.go": {
-    "mtime": 1786856664.2957466,
+    "mtime": 1786857336.6414917,
     "ast_hash": "d5f2248c3d11de74bf5a3977651b17c2",
     "semantic_hash": ""
   },
@@ -570,8 +570,8 @@
     "semantic_hash": "60d9eb7c59a3751baf4f31c7655217e7"
   },
   "backend/internal/latest/acquire.go": {
-    "mtime": 1786499529.7688599,
+    "mtime": 1786859346.3297389,
-    "ast_hash": "6c1ad34bbe9f5b49d0fd1eae9093f55d",
+    "ast_hash": "d605e3c94a62fc7787efbc139696b9d2",
     "semantic_hash": ""
   },
   "backend/internal/latest/acquire_test.go": {
@@ -615,8 +615,8 @@
     "semantic_hash": ""
   },
   "backend/internal/latest/read.go": {
-    "mtime": 1786499529.7688599,
+    "mtime": 1786859355.8679621,
-    "ast_hash": "3cf29046ddaef39fafb1df70b9f9ae8c",
+    "ast_hash": "9f039cc3ad74f803d7621f7ef4157bf2",
     "semantic_hash": ""
   },
   "docs/research/cloudflare-bot-scoring-and-poll-cadence.md": {
@@ -625,8 +625,13 @@
     "semantic_hash": ""
   },
   "backend/internal/latest/smoke_comix_test.go": {
-    "mtime": 1786856356.3432186,
+    "mtime": 1786857336.6414917,
     "ast_hash": "111fdbb75fc68ac2ab1013bc916063cf",
     "semantic_hash": ""
+  },
+  "docs/adr/0010-poll-lanes-per-site-pace.md": {
+    "mtime": 1786860214.4637265,
+    "ast_hash": "dc19d75f034ca920d93b9c71e6ca28e6",
+    "semantic_hash": ""
   }
 }