backend/AGENTS.md

@@ -27,7 +27,8 @@ Guidance for OpenCode (and Claude Code) working under `backend/`. See root `AGEN
   `series` keyed `(site, series_id)`
   (`asura`|`demonic`|`comix`|`kagane`|`novelfull`|`lightnovelworld`) owns the
   shared facts — title, cover, canonical URL, `kind` (`manga`|`novel`),
-  Latest Chapter, `latest_checked_at` — and `bookmarks` holds only what
+  Latest Chapter, `latest_checked_at`, and the Sighting pair
+  `latest_sighted_at`/`latest_raised_by` (issue #103) — and `bookmarks` holds only what
   differs between readers: progress, favourite, lifecycle bucket,
   `updated_at`. A bookmark is keyed `(reader_id, site, series_id)` — no
   surrogate id; the wire `key` is derived as `site:series_id` on read — and
@@ -78,7 +79,9 @@ Guidance for OpenCode (and Claude Code) working under `backend/`. See root `AGEN
   each re-checking that Site's bookmarked series' newest published chapter from
   backend's own network access, so `latest_chapter` stays fresh when the user
   isn't browsing. Second, parallel signal — the userscript keeps its own
-  `maybeCaptureLatestOnSeriesPage`/`backgroundRefreshLatest` logic unchanged.
+  `maybeCaptureLatestOnSeriesPage`/`backgroundRefreshLatest` schedule, and its
+  `reportLatestChapter` PUTs every read, unchanged numbers included, because an
+  unchanged read is exactly the Sighting worth deferring a Poll on (#103).
   Two independent clocks: per-series rest (`series.latest_checked_at`,
   enforced by `Store.DueForLatestCheck`'s WHERE clause — `now - Rest`) and
   per-Lane gap (the Lane sleeping between fetches, `effectiveGap`). Both live
@@ -91,6 +94,29 @@ Guidance for OpenCode (and Claude Code) working under `backend/`. See root `AGEN
   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.
+  **Sightings** (issue #103, ADR-0011) let a Reader's own page read defer a
+  Poll: `Store.RecordSighting` — called by the PUT handler *before* the Upsert,
+  because the raise test needs the row as it stands — stamps
+  `series.latest_sighted_at` and, when the report raises the stored number,
+  names its Reader in `series.latest_raised_by`. The due query's HAVING clause
+  is where deferral lives: a Series is skipped only while it has exactly one
+  Bookmark, was sighted within one Rest, and is under the ceiling
+  (`sightingCeilingRests`, six of that Site's rests) since its last Poll. So a
+  shared Series is never deferred, and no Series goes six hours unpolled
+  whatever arrives. `checkOne` judges the named Reader off the comparison it
+  already makes: a lower number is a contradiction (logged with the Reader and
+  both numbers), the same number an agreement, a higher number the Site
+  publishing and neither — that last one clears the attribution instead, since
+  the value the Poll then stores is its own and a later retraction is not the
+  Reader's fault. Three contradictions
+  (`store.SightingDisagreementLimit`) stop that Reader deferring — their
+  reports still write the Latest Chapter — and twenty consecutive agreements
+  (`store.SightingAgreementsToClear`) forgive them, as does the owner's
+  clear-marks control. Deferral is recomputed from live facts every round, so
+  nothing needs invalidating when a Series gains a second Bookmark; the one
+  input read earlier is the Reader's marks, checked when the Sighting is
+  recorded, so crossing the threshold or being cleared takes effect from that
+  Reader's next Sighting and the standing already bought lasts out its rest.
   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

backend/api_test.go

@@ -621,6 +621,46 @@ func TestPutDoesNotClobberLatestCheckedAt(t *testing.T) {
 	}
 }
 
+// Sighting deferral (issue #103) only reaches production through the PUT
+// handler: the store and poller can be right and the feature still dead if the
+// handler never records the report. Asserted where a client can see it - the
+// series stops being due the moment the PUT lands.
+func TestPutRecordsASighting(t *testing.T) {
+	s := newTestStore(t)
+	srv := newRouter(s, testConfig(), nil)
+
+	now := time.Now().UnixMilli()
+	hour := time.Hour.Milliseconds()
+	seedForCheck(t, s, "asura:x", "https://asurascans.com/comics/x", now-2*hour)
+	due, err := s.DueForLatestCheck("asura", now-hour, now-6*hour)
+	if err != nil {
+		t.Fatalf("DueForLatestCheck: %v", err)
+	}
+	if len(due) != 1 {
+		t.Fatalf("due before the PUT = %d series, want 1", len(due))
+	}
+
+	body := `{"key":"asura:x","site":"asura","series_id":"x",
+		"series_url":"https://asurascans.com/comics/x",
+		"last_chapter":"Chapter 5","last_chapter_num":5,
+		"latest_chapter":"Chapter 9","latest_chapter_num":9}`
+	req := httptest.NewRequest(http.MethodPut, "/bookmarks/asura:x", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	srv.ServeHTTP(rec, auth(req))
+	if rec.Code != http.StatusOK {
+		t.Fatalf("PUT status = %d, want 200 (body %s)", rec.Code, rec.Body.String())
+	}
+
+	due, err = s.DueForLatestCheck("asura", now-hour, now-6*hour)
+	if err != nil {
+		t.Fatalf("DueForLatestCheck: %v", err)
+	}
+	if len(due) != 0 {
+		t.Fatalf("due after the PUT = %d series, want 0: the handler recorded no Sighting", len(due))
+	}
+}
+
 // The userscript route is registered outside the web UI's Discord auth, so it
 // must keep working whatever the web config — see internal/userscript for the
 // handler's own behaviour. The credential in the path is the owner's derived

backend/internal/api/handlers.go

@@ -99,7 +99,18 @@ func (h *Handler) Put(w http.ResponseWriter, r *http.Request) {
 	// reading progress actually moved. Any client value is ignored.
 	b.UpdatedAt = time.Now().UnixMilli()
 
-	stored, err := h.Store.Upsert(httpmw.ReaderID(r), b)
+	// A userscript PUT is a Sighting: the Reader's browser was on the Series
+	// page and read its Latest Chapter (issue #103). Recorded before the
+	// Upsert, which is what makes the raise comparison possible, and never
+	// from the web UI's own read-modify-write — a Reader toggling a favourite
+	// has not looked at the Site and must not postpone a Poll. A failure here
+	// costs a deferral, not the write, so it is logged and dropped.
+	readerID := httpmw.ReaderID(r)
+	if err := h.Store.RecordSighting(readerID, b.Site, b.SeriesID, b.LatestChapterNum, b.UpdatedAt); err != nil {
+		log.Printf("record sighting: %v", err)
+	}
+
+	stored, err := h.Store.Upsert(readerID, b)
 	if err != nil {
 		log.Printf("upsert: %v", err)
 		http.Error(w, "internal error", http.StatusInternalServerError)

backend/internal/latest/poller.go

@@ -250,7 +250,8 @@ func (p *Poller) runLanePass(ctx context.Context, name string, paced bool) time.
 		return defaultGap
 	}
 
-	due, err := p.Store.DueForLatestCheck(name, now.Add(-s.Rest).UnixMilli())
+	due, err := p.Store.DueForLatestCheck(name, now.Add(-s.Rest).UnixMilli(),
+		now.Add(-sightingCeilingRests*s.Rest).UnixMilli())
 	if err != nil {
 		log.Printf("latest poll %s: due query: %v", name, err)
 		st.Gap = defaultGap
@@ -461,6 +462,11 @@ func (p *Poller) checkOne(ctx context.Context, sr store.Series) error {
 		return nil
 	}
 
+	// The Poll is the oracle for whatever Sighting last raised this Series
+	// (issue #103), and the judgement is free: the comparison below already
+	// exists, and no extra request is made to reach it.
+	p.judgeSighting(sr, facts.Latest.Num)
+
 	// Equality, not >, mirroring the userscript (L427): a site that retracts a
 	// chapter should correct the stored number downward. The comparison is
 	// against the due-query snapshot; a concurrent write in between only costs
@@ -481,6 +487,43 @@ func (p *Poller) checkOne(ctx context.Context, sr store.Series) error {
 	return nil
 }
 
+// judgeSighting settles the Sighting the Series' stored Latest Chapter is owed
+// to, if any, against what the Site actually publishes. The asymmetry is the
+// whole of the detection rule and is what keeps it free of false alarms: a Poll
+// finding a *lower* number than stored means the Reader who raised it reported
+// a chapter that does not exist, while a Poll finding a higher one is only the
+// Site publishing since and means nothing about the report. Equality confirms
+// the report, which is how an honest Reader earns back a mark.
+//
+// A Series with no attribution — the stored value is a Poll's own, or a
+// previous Poll already judged the report — is nobody's to answer for.
+func (p *Poller) judgeSighting(sr store.Series, found float64) {
+	if sr.LatestRaisedBy == nil || sr.LatestChapterNum == nil {
+		return
+	}
+	stored := *sr.LatestChapterNum
+	if found > stored {
+		// The report is neither confirmed nor contradicted, but it is answered:
+		// the value about to be stored is the Poll's own, so leaving the
+		// attribution would credit this Reader with the next Poll's agreement
+		// and blame them if the Site later retracts.
+		if err := p.Store.ClearSightingAttribution(sr.Site, sr.SeriesID, *sr.LatestRaisedBy); err != nil {
+			log.Printf("latest poll %q: clear sighting attribution: %v", sr.Key(), err)
+		}
+		return
+	}
+	if found < stored {
+		// Logged with both numbers and the Reader, because that is what tells a
+		// broken Site adapter (which marks every Reader of that Site at once)
+		// from one Reader deliberately lying.
+		log.Printf("latest poll %q: sighting contradicted: reader %d raised it to %v, site publishes %v",
+			sr.Key(), *sr.LatestRaisedBy, stored, found)
+	}
+	if err := p.Store.RecordSightingOutcome(sr.Site, sr.SeriesID, *sr.LatestRaisedBy, found == stored); err != nil {
+		log.Printf("latest poll %q: record sighting outcome: %v", sr.Key(), err)
+	}
+}
+
 // 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

backend/internal/latest/sighting_test.go

@@ -0,0 +1,494 @@
+package latest
+
+import (
+	"context"
+	"crypto/sha256"
+	"fmt"
+	"log"
+	"strings"
+	"testing"
+	"time"
+
+	"bookmarkmanager/backend/internal/store"
+)
+
+// Sightings (issue #103) are specified at the Poller seam, with the store as
+// the way in: a Sighting is seeded the way handlers.Put performs one, a round
+// is run against the injected fetcher and a frozen clock, and the assertions
+// are the two observable facts — whether the Series was fetched, and what the
+// stored Latest Chapter is afterwards. Nothing here asserts counter arithmetic
+// through an internal call or reads how a deferral is represented in a row.
+
+const (
+	sightingSlug = "chronicles-of-the-demon-faction-f886a8af"
+	sightingKey  = "asura:" + sightingSlug
+	sightingURL  = "https://asurascans.com/comics/" + sightingSlug
+)
+
+// sightingFixtureLatest is the newest chapter asuraSeriesFixture publishes.
+const sightingFixtureLatest = 181.0
+
+// sight performs one Sighting exactly as the JSON API does (handlers.Put):
+// RecordSighting against the row as stored, then the Upsert that stores the
+// reported value. The order is load-bearing — the raise comparison has nothing
+// to compare against once the Upsert has landed — and the bookmark's own fields
+// are carried over untouched, which is what a userscript PUT does when it
+// echoes back the row it cached.
+func sight(t *testing.T, s *store.Store, readerID int64, key string, num float64, at time.Time) {
+	t.Helper()
+	site, seriesID, ok := strings.Cut(key, ":")
+	if !ok {
+		t.Fatalf("key %q: no ':' separator", key)
+	}
+	b, found, err := s.Get(readerID, key)
+	if err != nil || !found {
+		t.Fatalf("sight %q: get: %v found=%v", key, err, found)
+	}
+	if err := s.RecordSighting(readerID, site, seriesID, &num, at.UnixMilli()); err != nil {
+		t.Fatalf("sight %q: %v", key, err)
+	}
+	b.LatestChapter = fmt.Sprintf("Chapter %v", num)
+	b.LatestChapterNum = &num
+	b.UpdatedAt = at.UnixMilli()
+	if _, err := s.Upsert(readerID, b); err != nil {
+		t.Fatalf("sight %q: upsert: %v", key, err)
+	}
+}
+
+// secondReader is another Reader on the same database. The owner seed is the
+// only reader-creation path in this package, so a second Open as a different
+// owner is how a test gets one (as TestRunOnceFetchesSharedSeriesOnce does).
+func secondReader(t *testing.T, dbURL string) *store.Store {
+	t.Helper()
+	other, err := store.Open(dbURL,
+		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() })
+	return other
+}
+
+func readLatestNum(t *testing.T, s *store.Store, readerID int64, key string) float64 {
+	t.Helper()
+	b, ok, err := s.Get(readerID, key)
+	if err != nil || !ok {
+		t.Fatalf("Get %q: %v ok=%v", key, err, ok)
+	}
+	if b.LatestChapterNum == nil {
+		t.Fatalf("%q has no latest chapter", key)
+	}
+	return *b.LatestChapterNum
+}
+
+// A Series only one Reader bookmarks is the case where being wrong can hurt
+// nobody but the Reader who reported it, so their Sighting stands in for the
+// Poll and the round leaves the Series alone.
+func TestSightingOnSolitarySeriesDefersPoll(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedForCheck(t, s, sightingKey, sightingURL, now.Add(-2*time.Hour).UnixMilli())
+	sight(t, s, s.OwnerID(), sightingKey, sightingFixtureLatest, now.Add(-10*time.Minute))
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	newTestPoller(t, s, f, now).runOnce(context.Background())
+
+	if got := f.callCount(); got != 0 {
+		t.Fatalf("fetched %d times after a Sighting on a solitary Series, want 0", got)
+	}
+}
+
+// On a shared Series the Sighting still writes the Latest Chapter for everyone,
+// but the Poll happens on schedule anyway — which is what corrects a wrong
+// value within the hour instead of letting it persist.
+func TestSightingOnSharedSeriesDoesNotDeferPoll(t *testing.T) {
+	s, dbURL := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedForCheck(t, s, sightingKey, sightingURL, now.Add(-2*time.Hour).UnixMilli())
+	other := secondReader(t, dbURL)
+	if _, err := s.Upsert(other.OwnerID(), store.Bookmark{
+		Key: sightingKey, Site: "asura", SeriesID: sightingSlug, UpdatedAt: 2000,
+	}); err != nil {
+		t.Fatalf("seed second reader: %v", err)
+	}
+	sight(t, s, s.OwnerID(), sightingKey, 200, now.Add(-10*time.Minute))
+
+	// The Sighting updated the shared row immediately, before any Poll.
+	if got := readLatestNum(t, s, s.OwnerID(), sightingKey); got != 200 {
+		t.Fatalf("latest after the Sighting = %v, want 200", got)
+	}
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	newTestPoller(t, s, f, now).runOnce(context.Background())
+
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("fetched %d times after a Sighting on a shared Series, want 1", got)
+	}
+	if got := readLatestNum(t, s, s.OwnerID(), sightingKey); got != sightingFixtureLatest {
+		t.Fatalf("latest after the Poll = %v, want the Site's own %v", got, sightingFixtureLatest)
+	}
+}
+
+// Reporting a chapter is not reading one: a Sighting may move the Latest
+// Chapter and nothing else. Both the solitary and the shared case, because the
+// deferral branch must not be where this guarantee lives.
+func TestSightingLeavesProgressAndOrderingUntouched(t *testing.T) {
+	for _, shared := range []bool{false, true} {
+		name := "solitary"
+		if shared {
+			name = "shared"
+		}
+		t.Run(name, func(t *testing.T) {
+			s, dbURL := newTestStore(t)
+			read := 5.0
+			if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+				Key: sightingKey, Site: "asura", SeriesID: sightingSlug, SeriesURL: sightingURL,
+				LastChapter: "Chapter 5", LastChapterNum: read,
+				LastChapterURL: sightingURL + "/chapter/5", UpdatedAt: 1000,
+			}); err != nil {
+				t.Fatalf("seed: %v", err)
+			}
+			if shared {
+				other := secondReader(t, dbURL)
+				if _, err := s.Upsert(other.OwnerID(), store.Bookmark{
+					Key: sightingKey, Site: "asura", SeriesID: sightingSlug, UpdatedAt: 2000,
+				}); err != nil {
+					t.Fatalf("seed second reader: %v", err)
+				}
+			}
+
+			sight(t, s, s.OwnerID(), sightingKey, 200, time.UnixMilli(9_000_000))
+
+			b, ok, err := s.Get(s.OwnerID(), sightingKey)
+			if err != nil || !ok {
+				t.Fatalf("Get: %v ok=%v", err, ok)
+			}
+			if b.LatestChapterNum == nil || *b.LatestChapterNum != 200 {
+				t.Fatalf("LatestChapterNum = %v, want 200", b.LatestChapterNum)
+			}
+			if b.LastChapterNum != read {
+				t.Fatalf("LastChapterNum = %v, want %v: a Sighting is not Progress", b.LastChapterNum, read)
+			}
+			if b.UpdatedAt != 1000 {
+				t.Fatalf("updated_at moved to %d: a Sighting must not reorder the list", b.UpdatedAt)
+			}
+		})
+	}
+}
+
+// The ceiling is what makes trusting a client report safe: however recently a
+// Series was sighted, one that has not been Polled in six hours is Polled.
+func TestSightingCeilingForcesPoll(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedForCheck(t, s, sightingKey, sightingURL, now.Add(-7*time.Hour).UnixMilli())
+	sight(t, s, s.OwnerID(), sightingKey, sightingFixtureLatest, now.Add(-time.Minute))
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	newTestPoller(t, s, f, now).runOnce(context.Background())
+
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("fetched %d times past the %s ceiling, want 1", got, sightingCeilingRests*defaultRest)
+	}
+}
+
+// Deferral is decided from live facts every round, so a Series that gains a
+// second Bookmark stops deferring at once — and one that loses it defers again.
+func TestDeferralFollowsTheBookmarkCount(t *testing.T) {
+	s, dbURL := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedForCheck(t, s, sightingKey, sightingURL, now.Add(-2*time.Hour).UnixMilli())
+	sight(t, s, s.OwnerID(), sightingKey, sightingFixtureLatest, now.Add(-10*time.Minute))
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	p := newTestPoller(t, s, f, now)
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 0 {
+		t.Fatalf("solitary Series fetched %d times, want 0", got)
+	}
+
+	other := secondReader(t, dbURL)
+	if _, err := s.Upsert(other.OwnerID(), store.Bookmark{
+		Key: sightingKey, Site: "asura", SeriesID: sightingSlug, UpdatedAt: 2000,
+	}); err != nil {
+		t.Fatalf("seed second reader: %v", err)
+	}
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("shared Series fetched %d times, want 1", got)
+	}
+
+	// The Poll above consumed the rest, so move past it before asking again.
+	if err := other.Delete(other.OwnerID(), sightingKey); err != nil {
+		t.Fatalf("delete second bookmark: %v", err)
+	}
+	later := now.Add(2 * time.Hour)
+	p.Now = func() time.Time { return later }
+	sight(t, s, s.OwnerID(), sightingKey, sightingFixtureLatest, later.Add(-time.Minute))
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("Series fetched %d times after returning to one Bookmark, want 1", got)
+	}
+}
+
+// A Series nobody reports any more returns to the normal schedule on its own:
+// the Sighting's standing lasts one rest, not forever.
+func TestDeferralExpiresWithoutFurtherSightings(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedForCheck(t, s, sightingKey, sightingURL, now.Add(-2*time.Hour).UnixMilli())
+	sight(t, s, s.OwnerID(), sightingKey, sightingFixtureLatest, now.Add(-10*time.Minute))
+
+	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
+	p := newTestPoller(t, s, f, now)
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 0 {
+		t.Fatalf("fetched %d times while the Sighting stood, want 0", got)
+	}
+
+	p.Now = func() time.Time { return now.Add(90 * time.Minute) }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("fetched %d times once the Sighting aged out, want 1", got)
+	}
+}
+
+// demonicFixture publishes one chapter in demonicscans' live page shape, so a
+// test can make a Site publish an arbitrary number rather than the one the
+// captured fixture froze.
+func demonicFixture(num float64) string {
+	return fmt.Sprintf(
+		`<a  href="/chaptered.php?manga=11799&chapter=%v" class="chplinks" title="Catastrophic Necromancer %v">Chapter %v</a>`,
+		num, num, num)
+}
+
+const (
+	demonicKey = "demonic:Catastrophic-Necromancer"
+	demonicURL = "https://demonicscans.org/manga/Catastrophic-Necromancer"
+)
+
+// contradictOnce reports a chapter that does not exist and then runs the round
+// that catches it, returning when that round ran so a caller can chain the
+// next one. The wait is one rest and a minute: a Sighting stands in for exactly
+// one rest, so that is the first moment this solitary Series is Polled again.
+func contradictOnce(t *testing.T, s *store.Store, p *Poller, sightAt time.Time, real float64) time.Time {
+	t.Helper()
+	sight(t, s, s.OwnerID(), demonicKey, real+500, sightAt)
+	at := sightAt.Add(defaultRest + time.Minute)
+	p.Now = func() time.Time { return at }
+	p.runOnce(context.Background())
+	if got := readLatestNum(t, s, s.OwnerID(), demonicKey); got != real {
+		t.Fatalf("latest after the Poll = %v, want the Site's own %v", got, real)
+	}
+	return at
+}
+
+func seedDemonic(t *testing.T, s *store.Store, checkedAt int64) {
+	t.Helper()
+	seedForCheck(t, s, demonicKey, demonicURL, checkedAt)
+}
+
+// A Poll finding a lower number than stored means the Sighting that raised it
+// was false. The Reader is named — not the Series flagged — and both numbers are
+// logged, because that is what tells a broken adapter from a deliberate lie.
+func TestPollContradictingASightingNamesTheReaderAndBothNumbers(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, now.Add(-2*time.Hour).UnixMilli())
+
+	var logs strings.Builder
+	prev := log.Writer()
+	log.SetOutput(&logs)
+	t.Cleanup(func() { log.SetOutput(prev) })
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, now)
+	contradictOnce(t, s, p, now, 296)
+
+	got := logs.String()
+	for _, want := range []string{
+		fmt.Sprintf("reader %d", s.OwnerID()), "796", "296", demonicKey,
+	} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("contradiction log = %q, want it to name %q", got, want)
+		}
+	}
+}
+
+// Three contradictions cost the Reader the right to defer. Nothing here writes
+// a counter: the marks are earned through Polls, which is the only way
+// production produces them.
+func TestThreeContradictionsStopDeferral(t *testing.T) {
+	s, _ := newTestStore(t)
+	start := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, start.Add(-2*time.Hour).UnixMilli())
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, start)
+	at := start
+	for range store.SightingDisagreementLimit {
+		at = contradictOnce(t, s, p, at.Add(time.Minute), 296)
+	}
+	fetchesSoFar := f.callCount()
+
+	// The marked Reader sights the same solitary Series again. It still writes
+	// the Latest Chapter — the penalty removes a privilege, it does not silence
+	// anyone — but the Poll is no longer postponed: the round below runs while a
+	// trusted Reader's Sighting would still be standing, and fetches anyway.
+	sight(t, s, s.OwnerID(), demonicKey, 900, at.Add(31*time.Minute))
+	if got := readLatestNum(t, s, s.OwnerID(), demonicKey); got != 900 {
+		t.Fatalf("latest after a marked Reader's Sighting = %v, want 900", got)
+	}
+	p.Now = func() time.Time { return at.Add(defaultRest + time.Minute) }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != fetchesSoFar+1 {
+		t.Fatalf("marked Reader's Sighting still deferred the Poll (fetches %d, want %d)",
+			got, fetchesSoFar+1)
+	}
+}
+
+// The owner's remedy for a mark a broken Site adapter produced restores the
+// privilege without a wait and without SQL.
+func TestClearingMarksRestoresDeferral(t *testing.T) {
+	s, _ := newTestStore(t)
+	start := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, start.Add(-2*time.Hour).UnixMilli())
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, start)
+	at := start
+	for range store.SightingDisagreementLimit {
+		at = contradictOnce(t, s, p, at.Add(time.Minute), 296)
+	}
+	if err := s.ClearReaderMarks(s.OwnerID()); err != nil {
+		t.Fatalf("ClearReaderMarks: %v", err)
+	}
+
+	fetchesSoFar := f.callCount()
+	sight(t, s, s.OwnerID(), demonicKey, 900, at.Add(31*time.Minute))
+	p.Now = func() time.Time { return at.Add(defaultRest + time.Minute) }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != fetchesSoFar {
+		t.Fatalf("fetched %d times after the marks were cleared, want %d: deferral must resume",
+			got, fetchesSoFar)
+	}
+}
+
+// Recovery is automatic but expensive: twenty Polls that each confirm a
+// Sighting of this Reader's clear the marks. Each round needs a new chapter,
+// because only a report that raises the stored number is attributed and so only
+// that one can be confirmed.
+func TestTwentyAgreementsClearTheMarks(t *testing.T) {
+	s, _ := newTestStore(t)
+	start := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, start.Add(-2*time.Hour).UnixMilli())
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, start)
+	at := start
+	for range store.SightingDisagreementLimit {
+		at = contradictOnce(t, s, p, at.Add(time.Minute), 296)
+	}
+
+	chapter := 296.0
+	for range store.SightingAgreementsToClear {
+		chapter++
+		sight(t, s, s.OwnerID(), demonicKey, chapter, at.Add(time.Minute))
+		f.body = demonicFixture(chapter) // the Site publishes what was reported
+		at = at.Add(defaultRest + time.Minute)
+		p.Now = func() time.Time { return at }
+		p.runOnce(context.Background())
+	}
+
+	fetchesSoFar := f.callCount()
+	chapter++
+	sight(t, s, s.OwnerID(), demonicKey, chapter, at.Add(31*time.Minute))
+	p.Now = func() time.Time { return at.Add(defaultRest + time.Minute) }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != fetchesSoFar {
+		t.Fatalf("fetched %d times after %d confirmations, want %d: the marks must be forgiven",
+			got, store.SightingAgreementsToClear, fetchesSoFar)
+	}
+}
+
+// A Poll finding a higher number is the Site publishing since the Sighting and
+// means nothing about the Reader — no mark, and no credit either.
+func TestPollFindingHigherNumberIsNotAContradiction(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, now.Add(-2*time.Hour).UnixMilli())
+	// Reported truthfully, then the Site published one more.
+	sight(t, s, s.OwnerID(), demonicKey, 295, now.Add(-10*time.Minute))
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, now)
+	// One rest on, the Sighting has lapsed and the Poll happens.
+	p.Now = func() time.Time { return now.Add(7 * time.Hour) }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("fetched %d times past the ceiling, want 1", got)
+	}
+
+	// Unmarked, so a fresh Sighting still defers.
+	at := now.Add(9 * time.Hour)
+	sight(t, s, s.OwnerID(), demonicKey, 296, at.Add(-time.Minute))
+	p.Now = func() time.Time { return at }
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("a Reader whose report the Site overtook lost the right to defer (fetches %d, want 1)", got)
+	}
+}
+
+// A Poll that overtakes a Sighting takes ownership of the row: the value stored
+// afterwards is the Poll's own, so a later retraction is not the Reader's fault
+// and must not be charged to them.
+func TestAttributionDoesNotSurviveAPollThatOvertookIt(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, now.Add(-2*time.Hour).UnixMilli())
+	sight(t, s, s.OwnerID(), demonicKey, 295, now.Add(-10*time.Minute))
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, now)
+	at := now.Add(defaultRest + time.Minute)
+	p.Now = func() time.Time { return at }
+	p.runOnce(context.Background())
+	if got := readLatestNum(t, s, s.OwnerID(), demonicKey); got != 296 {
+		t.Fatalf("latest after the Poll = %v, want the Site's own 296", got)
+	}
+
+	var logs strings.Builder
+	prev := log.Writer()
+	log.SetOutput(&logs)
+	t.Cleanup(func() { log.SetOutput(prev) })
+
+	f.body = demonicFixture(290) // the Site retracts what only the Poll wrote
+	p.Now = func() time.Time { return at.Add(defaultRest + time.Minute) }
+	p.runOnce(context.Background())
+	if strings.Contains(logs.String(), "sighting contradicted") {
+		t.Fatalf("a retraction of the Poll's own value was charged to a Reader: %s", logs.String())
+	}
+}
+
+// A PUT with no Latest Chapter in it — a favourite toggle, progress written
+// from a chapter page — is nobody looking at the Series page, so it buys no
+// deferral. Otherwise a client could suppress a Series' Polls while reporting
+// nothing, and with nothing reported there would be nothing to judge.
+func TestPutWithoutALatestChapterDoesNotDefer(t *testing.T) {
+	s, _ := newTestStore(t)
+	now := time.UnixMilli(20 * time.Hour.Milliseconds())
+	seedDemonic(t, s, now.Add(-2*time.Hour).UnixMilli())
+	// The handler's own call, with the field the client omitted.
+	if err := s.RecordSighting(s.OwnerID(), "demonic", "Catastrophic-Necromancer",
+		nil, now.Add(-time.Minute).UnixMilli()); err != nil {
+		t.Fatalf("RecordSighting: %v", err)
+	}
+
+	f := &fakeFetcher{body: demonicFixture(296), status: 200}
+	p := newTestPoller(t, s, f, now)
+	p.runOnce(context.Background())
+	if got := f.callCount(); got != 1 {
+		t.Fatalf("fetched %d times after a PUT carrying no chapter, want 1", got)
+	}
+}

backend/internal/latest/sites.go

@@ -409,6 +409,14 @@ const (
 	// asleep (ADR-0005 on-demand browser).
 	browserWakeCount = 5
 	browserWakeAge   = 15 * time.Minute
+	// sightingCeilingRests caps Sighting deferral (issue #103): however many
+	// Sightings arrive, a Series unpolled for this many of its Site's rests is
+	// Polled. It is what makes a client report safe to trust — a wrong Latest
+	// Chapter dies within the ceiling deterministically, rather than in
+	// expectation the way a randomised audit would have it. Six, so a Series a
+	// Reader visits constantly still gets one authoritative check per working
+	// day-part.
+	sightingCeilingRests = 6
 )
 
 // effectiveGap is a Site's pace: the registry gap, or one rest divided by the

backend/internal/store/migrations/0011_series_sightings.sql

@@ -0,0 +1,10 @@
+-- Sighting deferral (issue #103). latest_sighted_at is when a Reader's report
+-- last stood in for a Poll; it is separate from latest_checked_at because the
+-- six-hour ceiling has to know when the Series was last really fetched, and a
+-- Sighting writing the Poll's own column would erase that.
+-- latest_raised_by is attribution: whoever last raised this Series' Latest
+-- Chapter by Sighting, so a Poll that contradicts the value downwards names a
+-- Reader rather than flagging a row. Cleared by the Poll that judges it, NULL
+-- whenever the stored value is the Poll's own.
+ALTER TABLE series ADD COLUMN latest_sighted_at bigint NOT NULL DEFAULT 0;
+ALTER TABLE series ADD COLUMN latest_raised_by bigint REFERENCES readers(id) ON DELETE SET NULL;

backend/internal/store/store.go

@@ -79,6 +79,11 @@ type Series struct {
 	LatestChapter    string
 	LatestChapterNum *float64 // nil until first captured
 	LatestCheckedAt  int64    // unix ms; see MarkLatestChecked
+	// LatestRaisedBy is the Reader whose Sighting last raised LatestChapter,
+	// and nil when the stored value is a Poll's own finding. It is what lets a
+	// Poll that contradicts the value downwards name a Reader instead of
+	// merely flagging the row (issue #103); the Poll that judges it clears it.
+	LatestRaisedBy *int64
 
 	// readerCount is the number of bookmarks referencing this series, filled
 	// only by the due-queue query that orders on it.
@@ -195,7 +200,7 @@ const bookmarkColumns = `b.site, b.series_id, s.title, s.series_url, s.cover_add
 // due query. latest_checked_at lives only on series — see MarkLatestChecked
 // for why it stays off every client-visible write.
 const seriesColumns = `s.site, s.series_id, s.title, s.series_url, s.cover, s.cover_address,
-	s.kind, s.latest_chapter, s.latest_chapter_num, s.latest_checked_at`
+	s.kind, s.latest_chapter, s.latest_chapter_num, s.latest_checked_at, s.latest_raised_by`
 
 // Owner is the person running the service: the first Reader, seeded at startup
 // so a fresh deployment has a library before anyone logs in. The seed makes
@@ -584,16 +589,17 @@ func (s *Store) scanBookmark(scan func(...any) error) (Bookmark, error) {
 }
 
 // scanSeries reads one row in seriesColumns order, plus the due query's
-// reader_count column. latest_chapter_num is NULL until the first capture,
-// same as on the bookmark read path.
+// reader_count column. latest_chapter_num and latest_raised_by are both
+// nullable, same as latest_chapter_num on the bookmark read path.
 func scanSeries(scan func(...any) error) (Series, error) {
 	var (
 		sr               Series
 		latestChapterNum sql.NullFloat64
+		latestRaisedBy   sql.NullInt64
 	)
 	if err := scan(
 		&sr.Site, &sr.SeriesID, &sr.Title, &sr.SeriesURL, &sr.Cover, &sr.CoverAddress,
-		&sr.Kind, &sr.LatestChapter, &latestChapterNum, &sr.LatestCheckedAt,
+		&sr.Kind, &sr.LatestChapter, &latestChapterNum, &sr.LatestCheckedAt, &latestRaisedBy,
 		&sr.readerCount,
 	); err != nil {
 		return Series{}, err
@@ -601,6 +607,9 @@ func scanSeries(scan func(...any) error) (Series, error) {
 	if latestChapterNum.Valid {
 		sr.LatestChapterNum = &latestChapterNum.Float64
 	}
+	if latestRaisedBy.Valid {
+		sr.LatestRaisedBy = &latestRaisedBy.Int64
+	}
 	return sr, nil
 }
 
@@ -947,7 +956,20 @@ 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(site string, cutoffMs int64) ([]Series, error) {
+//
+// ceilingMs is the Sighting deferral ceiling (issue #103): a Series whose last
+// real Poll is older than it appears however recently it was sighted. That is
+// what bounds the whole mechanism — a wrong Latest Chapter dies within the
+// ceiling deterministically rather than in expectation. Deferral itself is
+// decided here, from two facts the query already computes, so a Lane gains no
+// query per round: a Sighting younger than cutoffMs holds the Series back, but
+// only while COUNT(*) is 1. A Series a second Reader bookmarks is Polled on
+// schedule, so a wrong value the whole guild can see is corrected by a check
+// that was never postponed; on a solitary Series the only person a wrong value
+// reaches is the Reader who reported it. Whether the reporting Reader is
+// allowed to defer at all was settled when the Sighting was recorded — see
+// RecordSighting.
+func (s *Store) DueForLatestCheck(site string, cutoffMs, ceilingMs 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
@@ -957,7 +979,10 @@ func (s *Store) DueForLatestCheck(site string, cutoffMs int64) ([]Series, error)
 		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`, site, cutoffMs)
+		   AND (COUNT(*) > 1
+		        OR s.latest_sighted_at <= $2::bigint
+		        OR s.latest_checked_at <= $3::bigint)
+		ORDER BY reader_count DESC, s.latest_checked_at ASC`, site, cutoffMs, ceilingMs)
 	if err != nil {
 		return nil, fmt.Errorf("query due series: %w", err)
 	}
@@ -1044,3 +1069,111 @@ func (s *Store) SetLatestChapter(site, seriesID, label string, num float64) erro
 	}
 	return nil
 }
+
+// RecordSighting notes that a Reader's browser reported this Series' Latest
+// Chapter, which is the half of a Sighting the client body cannot express
+// (issue #103). It must be called *before* the Upsert that stores the reported
+// value: the raise test compares against what is still on the row, and after
+// the Upsert there is nothing left to compare with. A Series that does not
+// exist yet — the first Bookmark of it — is not a Sighting at all: nothing has
+// ever been Polled, so there is nothing to defer and nobody to attribute.
+//
+// Two independent effects, hence the two CASE arms. The deferral stamp is only
+// written for a Reader below the disagreement limit, so a marked Reader's
+// reports keep updating the Latest Chapter but stop postponing anything, and
+// clearing their marks restores the privilege on their next Sighting. The
+// attribution is written whenever the report raises the stored number,
+// including for a marked Reader — their Sightings are still judged, which is
+// how they earn the privilege back.
+//
+// num is the reported chapter number. A PUT that carries none — a favourite
+// toggle, or progress written from a chapter page — is no Sighting at all:
+// nobody read the Series page, so there is nothing to stand in for a Poll and
+// nothing that could later be judged.
+func (s *Store) RecordSighting(readerID int64, site, seriesID string, num *float64, ts int64) error {
+	if num == nil {
+		return nil
+	}
+	if _, err := s.db.Exec(`
+		UPDATE series SET
+		  latest_sighted_at = CASE
+		    WHEN (SELECT sighting_disagreements FROM readers WHERE id = $3) < $6
+		    THEN $4::bigint ELSE latest_sighted_at END,
+		  latest_raised_by = CASE
+		    WHEN latest_chapter_num IS NULL OR $5::double precision > latest_chapter_num
+		    THEN $3::bigint ELSE latest_raised_by END
+		WHERE site = $1 AND series_id = $2`,
+		site, seriesID, readerID, ts, *num, SightingDisagreementLimit); err != nil {
+		return fmt.Errorf("record sighting %s:%s: %w", site, seriesID, err)
+	}
+	return nil
+}
+
+// SightingAgreementsToClear is how many Polls must confirm a Reader's
+// Sightings in a row before their disagreements are forgiven. An agreement is
+// only recorded when a Poll later confirms a Sighting, so this is twenty Polls
+// of Series that Reader bookmarks — hours to days, not twenty page views. That
+// is the intended price: recovery is automatic but cannot be outwaited, and a
+// disagreement resets the run to zero, so credit cannot be banked in advance.
+const SightingAgreementsToClear = 20
+
+// RecordSightingOutcome settles what a Poll decided about the Reader whose
+// Sighting last raised this Series' Latest Chapter, and clears the attribution
+// in the same transaction so one Sighting is judged exactly once. agreed is
+// the Poll confirming the stored value; its opposite is the Poll finding a
+// lower number, which means the raise was false.
+//
+// A Poll finding a *higher* number is neither — the Site published — and takes
+// ClearSightingAttribution instead.
+func (s *Store) RecordSightingOutcome(site, seriesID string, readerID int64, agreed bool) error {
+	tx, err := s.db.Begin()
+	if err != nil {
+		return fmt.Errorf("begin sighting outcome %s:%s: %w", site, seriesID, err)
+	}
+	defer tx.Rollback()
+
+	// The run length is what "consecutive" means: a disagreement zeroes the
+	// agreements, and completing a run zeroes both, so the next run starts
+	// from nothing rather than forgiving every later disagreement instantly.
+	q := `UPDATE readers SET sighting_disagreements = sighting_disagreements + 1,
+	                         sighting_agreements = 0
+	      WHERE id = $1`
+	args := []any{readerID}
+	if agreed {
+		q = `UPDATE readers SET
+		       sighting_agreements = CASE WHEN sighting_agreements + 1 >= $2 THEN 0
+		                                  ELSE sighting_agreements + 1 END,
+		       sighting_disagreements = CASE WHEN sighting_agreements + 1 >= $2 THEN 0
+		                                     ELSE sighting_disagreements END
+		     WHERE id = $1`
+		args = append(args, SightingAgreementsToClear)
+	}
+	if _, err := tx.Exec(q, args...); err != nil {
+		return fmt.Errorf("record sighting outcome for reader %d: %w", readerID, err)
+	}
+	if _, err := tx.Exec(clearAttributionSQL, site, seriesID, readerID); err != nil {
+		return fmt.Errorf("clear sighting attribution %s:%s: %w", site, seriesID, err)
+	}
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("commit sighting outcome %s:%s: %w", site, seriesID, err)
+	}
+	return nil
+}
+
+// ClearSightingAttribution answers a Sighting without judging it: the Poll
+// found a higher number, so the value about to be stored is its own and this
+// Reader is no longer answerable for the row. Without it the next Poll's
+// agreement would be credited to a Reader who did not earn it.
+func (s *Store) ClearSightingAttribution(site, seriesID string, readerID int64) error {
+	if _, err := s.db.Exec(clearAttributionSQL, site, seriesID, readerID); err != nil {
+		return fmt.Errorf("clear sighting attribution %s:%s: %w", site, seriesID, err)
+	}
+	return nil
+}
+
+// clearAttributionSQL drops the attribution only while it still names the
+// Reader being judged: a Sighting landing between the due query's snapshot and
+// this write is a fresh, unjudged one and must not be erased by the previous
+// one's verdict.
+const clearAttributionSQL = `UPDATE series SET latest_raised_by = NULL
+	WHERE site = $1 AND series_id = $2 AND latest_raised_by = $3`

backend/internal/store/store_test.go

@@ -277,6 +277,10 @@ func seedForCheck(t *testing.T, s *Store, key, seriesURL string, checkedAt int64
 	}
 }
 
+// noCeiling is a Sighting deferral ceiling no Series can reach, for the tests
+// that predate the ceiling and are about rest, ordering or buckets instead.
+const noCeiling = int64(-1)
+
 func TestDueForLatestCheck(t *testing.T) {
 	const hour = int64(3600_000)
 	now := 10 * hour
@@ -298,7 +302,7 @@ func TestDueForLatestCheck(t *testing.T) {
 			s := newTestStore(t)
 			seedForCheck(t, s, "asura:x", tt.seriesURL, tt.checkedAt)
 
-			due, err := s.DueForLatestCheck("asura", now-hour)
+			due, err := s.DueForLatestCheck("asura", now-hour, noCeiling)
 			if err != nil {
 				t.Fatalf("DueForLatestCheck: %v", err)
 			}
@@ -319,7 +323,7 @@ func TestDueForLatestCheckOldestFirstAndScopedToSite(t *testing.T) {
 	// 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("asura", 1000)
+	due, err := s.DueForLatestCheck("asura", 1000, noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -499,7 +503,7 @@ func TestDueForLatestCheckSkipsFinishedKeepsArchived(t *testing.T) {
 		}
 	}
 
-	due, err := store.DueForLatestCheck("asura", time.Now().UnixMilli())
+	due, err := store.DueForLatestCheck("asura", time.Now().UnixMilli(), noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1005,7 +1009,7 @@ 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("asura", 1000)
+	due, err := s.DueForLatestCheck("asura", 1000, noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1031,7 +1035,7 @@ func TestDueForLatestCheckExcludesOrphanSeries(t *testing.T) {
 		t.Fatalf("seed orphan series: %v", err)
 	}
 
-	due, err := s.DueForLatestCheck("asura", 1000)
+	due, err := s.DueForLatestCheck("asura", 1000, noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1449,7 +1453,7 @@ func TestTwoReadersShareOneSeriesWithIndependentProgress(t *testing.T) {
 		t.Fatalf("series rows = %d, want 1 shared row for two bookmarks", series)
 	}
 
-	due, err := s.DueForLatestCheck("asura", time.Now().UnixMilli())
+	due, err := s.DueForLatestCheck("asura", time.Now().UnixMilli(), noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck: %v", err)
 	}
@@ -1465,7 +1469,7 @@ 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("asura", time.Now().UnixMilli())
+	due, err = s.DueForLatestCheck("asura", time.Now().UnixMilli(), noCeiling)
 	if err != nil {
 		t.Fatalf("DueForLatestCheck after delete: %v", err)
 	}

docs/adr/0011-sighting-deferral-trust-model.md

@@ -0,0 +1,139 @@
+# ADR-0011: Sightings — a Reader report defers a Poll where being wrong hurts only them
+
+Date: 2026-08-16
+Status: accepted
+
+## Decision
+
+A **Sighting** is the Latest Chapter the Reader's own browser read off the
+Series page and PUT to the backend. It is now allowed to stand in for a Poll,
+under one restriction and one ceiling:
+
+- **Solitary Series only.** A Sighting defers the Poll of a Series exactly one
+  Bookmark points at. A Series two Readers share is Polled on schedule no matter
+  how recently it was sighted.
+- **One rest of standing.** A Sighting postpones Polls for one Rest
+  (`defaultRest`, an hour), not forever: a Series nobody visits again returns to
+  the normal schedule by itself.
+- **Six-rest ceiling.** `sightingCeilingRests = 6`, counted in the Site's own
+  Rest — six hours everywhere today. However many Sightings arrive, a Series
+  unpolled that long is Polled.
+
+Both live in the due query's HAVING clause (`store.DueForLatestCheck`), beside
+the Rest cutoff — the same place the schedule has always been decided, so no
+timer and no second code path can disagree with it.
+
+Attribution and judgement:
+
+- `Store.RecordSighting` runs *before* the Upsert that stores the reported
+  value, because the raise test needs the row as it stands. A report that raises
+  the stored Latest Chapter names its Reader in `series.latest_raised_by`.
+- The Poll is the oracle. `Poller.checkOne` already compares what the Site
+  publishes against what is stored, so judgement costs no extra request: a lower
+  number contradicts the Sighting (`sighting_disagreements + 1`, both numbers and
+  the Reader logged), the same number confirms it (`sighting_agreements + 1`), a
+  **higher** number is the Site publishing and means nothing either way — but it
+  does clear the attribution (`Store.ClearSightingAttribution`), because the
+  value stored afterwards is the Poll's own and nobody must answer for it.
+- At `SightingDisagreementLimit` (3) that Reader's Sightings stop deferring
+  anything. They still write the Latest Chapter — the penalty removes a
+  privilege, it does not silence anyone.
+- `SightingAgreementsToClear` (20) consecutive confirmations forgive the
+  disagreements. A disagreement resets the run to zero.
+- The owner clears marks from the administration page (issue #102, shipped
+  first precisely so a false mark has a remedy the day the mechanism lands).
+
+One client change was required, and only one. Both userscripts stopped short of
+PUTting a read whose number had not moved (`applyLatestChapterIfChanged`), so
+the case this whole mechanism exists for — visiting a Series with nothing new —
+never reached the backend. `reportLatestChapter` now sends it, skipping only the
+local write and the re-render. A numberless PUT (favourite toggle, progress from
+a chapter page) is not a Sighting and defers nothing: nobody read the Series
+page, so there would be nothing to judge later.
+
+## Why
+
+Most of the backend's work was redundant. The userscript reads the Latest
+Chapter on every Series page visit; minutes later the Poll Lane fetches the same
+page for the same number. Deferring on a report converts a visit into a Poll
+saved, which is Lane capacity handed back to Series nobody is
+reading.
+
+The restriction is the whole safety argument, and it is about **blast radius**,
+not about trust arithmetic:
+
+- On a solitary Series, a wrong report can only mislead the Reader who made it.
+  There is nobody else's ember to falsify.
+- On a shared Series it could mislead someone else, so a report never postpones
+  anything there.
+
+The ceiling bounds the damage in time: a false value dies within six hours
+whatever happens, because the Poll that finds it is guaranteed. That is also
+what makes lying pointless — the six-hour audit is certain, not sampled, so a
+determined attacker buys at most three ceilings' worth of a wrong number on
+their own Series and then loses deferral entirely.
+
+The cost of recovery is deliberate. An agreement is only recorded when a later
+Poll confirms a Sighting, so twenty agreements are twenty Polls of Series that
+Reader bookmarks — hours to days of real time, not twenty page views. Waiting is
+therefore not a strategy, and credit cannot be banked in advance.
+
+## Tradeoffs and rejections
+
+- **Trusting a Sighting on a shared Series** rejected: it is the only case where
+  one Reader's mistake reaches another Reader's list, and no amount of
+  reputation makes that recoverable within the six-hour window.
+- **Cross-Reader agreement, voting, weighting, consensus scoring** rejected on
+  evidence: every truth-discovery method estimates source reliability by
+  comparing sources on the same object, and the standard survey states outright
+  that an object provided by very few sources cannot have its confidence
+  evaluated — Li, Gao, Meng, Li, Su, Zhao, Fan, Han, *A Survey on Truth
+  Discovery*, SIGMOD Record 45(1), 2016 (arXiv:1505.02463), §"Challenges" on
+  sparse sources. With the two Readers this backend actually has, a
+  disagreement is a coin flip. The Poll is an authoritative oracle, so it is
+  the only judge.
+- **A randomised audit** (Poll a fraction of deferred Series) rejected in favour
+  of the fixed ceiling. Sampling an oracle against untrusted reports is the
+  gold-question technique from crowdsourcing quality control — Le, Edmonds,
+  Hester, Biewald, *Ensuring quality in crowdsourced search relevance
+  evaluation: the effects of training question distribution*, SIGIR 2010
+  Workshop on Crowdsourcing for Search Evaluation, which inserts known answers
+  sporadically and adjusts each worker's trust from them. The ceiling is the
+  same idea made deterministic: sampling prices an attack in expectation, a
+  guaranteed six-hour audit prices it as a certainty, which is what makes the
+  solitary-Series rule defensible in one sentence.
+- **A trust *ratio*** (agreements over judgements, as that same gold-question
+  scheme uses) rejected for two thresholds: a ratio lets an attacker bank
+  credit first and spend it on lies later, and it needs the owner watching a
+  score to act. Three-and-twenty is a threshold both ways — a disagreement
+  resets the run to zero, so credit cannot be pre-bought, and recovery happens
+  without the owner in the loop.
+- **Blocking a marked Reader's writes** rejected: the Latest Chapter they report
+  is still the best available value, and their Sightings must keep being judged
+  or they could never earn the privilege back.
+- **Per-Series flagging** rejected in favour of per-Reader marks: a Series is
+  not the thing that can be wrong. Naming the Reader and logging both numbers is
+  also what distinguishes a broken Site adapter (every Reader of that Site
+  contradicted at once) from one bad actor.
+- **Timers or a background reputation job** rejected: deferral is recomputed
+  from live facts every round — Bookmark count and sighting timestamp — so a
+  Series that gains a second Bookmark stops deferring at once, with nothing to
+  invalidate. The Reader's marks are the one input read earlier, when the
+  Sighting is recorded rather than when the round runs: a Reader who crosses
+  the threshold, or has their marks cleared, changes behaviour from their next
+  Sighting on, and the standing they already bought lasts out its rest. That is
+  bounded by one rest and costs one subselect instead of joining `readers` into
+  the due query on every round.
+
+## Constraints preserved
+
+- A Sighting is not Progress: it may move the Latest Chapter and nothing else.
+  `updated_at` never moves, so a report cannot reorder the list (ADR-0004).
+- The Latest Chapter is a Series-level fact (ADR-0003): a Sighting writes the
+  shared row, so every Reader of a shared Series sees it immediately — deferral
+  is the only thing the solitary rule withholds.
+- Ember means new chapter only (`docs/design-system.md`): a marked Reader
+  renders no differently in their own list, and nothing about the trust model
+  reaches the Series list's colour.
+- The Poll remains authoritative. Where a Sighting and a Poll disagree, the
+  Poll's value is what gets stored.

graphify-out/.graphify_labels.json

@@ -40,6 +40,7 @@
   "38": "novel-logic.test.js",
   "39": "UI Critique 2026-07-26A",
   "40": "UI Critique 2026-07-26B",
+  "41": "Handler",
   "42": "pgtest.go",
   "43": "Issue Tracker & Triage",
   "44": "Ticket Workflow",
@@ -151,6 +152,7 @@
   "150": "Reviewer Subagent (opencode)",
   "151": "Finding Severity Rubric",
   "152": "Spec Compliance Review",
+  "154": "ADR-0011: Sightings — a Reader report defers a Poll where being wrong hurts only them",
   "156": "ResponseWriter",
   "161": "Why Use samber/oops",
   "162": "singleflight Cache Stampede Prevention",

graphify-out/GRAPH_REPORT.md

@@ -1,16 +1,16 @@
 # Graph Report - mangaBookmark  (2026-08-16)
 
 ## Corpus Check
-- 116 files · ~284,419 words
+- 119 files · ~290,953 words
 - Verdict: corpus is large enough that graph structure adds value.
 
 ## Summary
-- 1701 nodes · 3463 edges · 219 communities (69 shown, 150 thin omitted)
-- Extraction: 91% EXTRACTED · 9% INFERRED · 0% AMBIGUOUS · INFERRED: 326 edges (avg confidence: 0.77)
+- 1736 nodes · 3597 edges · 221 communities (70 shown, 151 thin omitted)
+- Extraction: 90% EXTRACTED · 10% INFERRED · 0% AMBIGUOUS · INFERRED: 361 edges (avg confidence: 0.78)
 - Token cost: 0 input · 0 output
 
 ## Graph Freshness
-- Built from commit: `58014eb8`
+- Built from commit: `56afb9f2`
 - Run `git rev-parse HEAD` and compare to check if the graph is stale.
 - Run `graphify update .` after code changes (no API cost).
 
@@ -55,6 +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_Handler|Handler]]
 - [[_COMMUNITY_pgtest.go|pgtest.go]]
 - [[_COMMUNITY_Issue Tracker & Triage|Issue Tracker & Triage]]
 - [[_COMMUNITY_Ticket Workflow|Ticket Workflow]]
@@ -166,6 +167,7 @@
 - [[_COMMUNITY_Reviewer Subagent (opencode)|Reviewer Subagent (opencode)]]
 - [[_COMMUNITY_Finding Severity Rubric|Finding Severity Rubric]]
 - [[_COMMUNITY_Spec Compliance Review|Spec Compliance Review]]
+- [[_COMMUNITY_ADR-0011 Sightings — a Reader report defers a Poll where being wrong hurts only them|ADR-0011: Sightings — a Reader report defers a Poll where being wrong hurts only them]]
 - [[_COMMUNITY_ResponseWriter|ResponseWriter]]
 - [[_COMMUNITY_Why Use samberoops|Why Use samber/oops]]
 - [[_COMMUNITY_singleflight Cache Stampede Prevention|singleflight Cache Stampede Prevention]]
@@ -235,16 +237,16 @@
 - [[_COMMUNITY_Userscript CLAUDE guidance|Userscript CLAUDE guidance]]
 
 ## God Nodes (most connected - your core abstractions)
-1. `testConfig()` - 54 edges
-2. `newTestStore()` - 49 edges
+1. `newTestStore()` - 62 edges
+2. `testConfig()` - 55 edges
 3. `newWebTestServer()` - 49 edges
 4. `newTestStore()` - 44 edges
 5. `e()` - 33 edges
-6. `Open()` - 30 edges
-7. `Handler` - 29 edges
-8. `Store` - 28 edges
-9. `ne()` - 28 edges
-10. `De()` - 28 edges
+6. `Store` - 31 edges
+7. `Open()` - 31 edges
+8. `newTestPoller()` - 30 edges
+9. `Handler` - 29 edges
+10. `ne()` - 28 edges
 
 ## Surprising Connections (you probably didn't know these)
 - `el()` --indirect_call--> `c()`  [INFERRED]
@@ -268,7 +270,7 @@
 - **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 (219 total, 150 thin omitted)
+## Communities (221 total, 151 thin omitted)
 
 ### Community 0 - "HTMX Library Internals"
 Cohesion: 0.08
@@ -280,23 +282,23 @@ Nodes (89): floatPtr(), testConfig(), getCover(), Cookie, Handler, ResponseRecor
 
 ### Community 2 - "Manga Userscript Adapters"
 Cohesion: 0.06
-Nodes (76): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+68 more)
+Nodes (77): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), armDwell() (+69 more)
 
 ### Community 3 - "Novel Userscript Adapters"
 Cohesion: 0.06
-Nodes (79): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLatestChapterIfChanged() (+71 more)
+Nodes (78): adapterFor(), anchorsFromDocument(), anchorsFromHTML(), apiDelete(), apiGet(), apiPut(), applyFabPos(), applyLnwStaleRowRepair() (+70 more)
 
 ### Community 4 - "Series Acquisition Tests"
-Cohesion: 0.08
-Nodes (78): bookmarkNewKaganeSeries(), bookmarkNewNovelfullSeries(), bookmarkNewSeries(), Context, Store, T, newAcquirer(), readBookmark() (+70 more)
+Cohesion: 0.07
+Nodes (103): bookmarkNewKaganeSeries(), bookmarkNewNovelfullSeries(), bookmarkNewSeries(), Context, Store, T, newAcquirer(), readBookmark() (+95 more)
 
 ### Community 5 - "Bookmarks API Tests"
 Cohesion: 0.07
-Nodes (70): auth(), getBookmarks(), Handler, Request, Store, T, newTestServer(), newTestStore() (+62 more)
+Nodes (71): auth(), getBookmarks(), Handler, Request, Store, T, newTestServer(), newTestStore() (+63 more)
 
 ### Community 7 - "Cover & Acquire Internals"
-Cohesion: 0.07
-Nodes (43): Addr, fakeLanes, Context, Store, WaitGroup, defaultCoverResolver(), fetchCoverBytes(), Client (+35 more)
+Cohesion: 0.06
+Nodes (43): Addr, fakeLanes, Context, Store, WaitGroup, isInterstitial(), defaultCoverResolver(), fetchCoverBytes() (+35 more)
 
 ### Community 8 - "System Architecture Concepts"
 Cohesion: 0.15
@@ -318,10 +320,6 @@ Nodes (45): Store, T, newTestStore(), readLatestCheckedAt(), readSeries(), secon
 Cohesion: 0.08
 Nodes (32): Handler, Request, ResponseWriter, Store, Healthz(), writeJSON(), Auth(), compressible() (+24 more)
 
-### Community 13 - "Web UI Handlers"
-Cohesion: 0.14
-Nodes (18): currentLib(), currentTab(), filterBookmarks(), Client, HandlerFunc, Request, ResponseWriter, Store (+10 more)
-
 ### Community 14 - "Go Error Handling"
 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)
@@ -368,7 +366,7 @@ Nodes (12): coverResponse(), Request, T, TestCoverFetcherCanonicalisesJpgAlias()
 
 ### Community 26 - "Open"
 Cohesion: 0.05
-Nodes (62): awaitPromise(), browserConnectionLost(), classifyBrowserError(), comixRead(), comixSeriesPageURL(), Action, Context, Mutex (+54 more)
+Nodes (61): awaitPromise(), browserConnectionLost(), classifyBrowserError(), comixRead(), comixSeriesPageURL(), Action, Context, Mutex (+53 more)
 
 ### Community 27 - "Find Skills Guide"
 Cohesion: 0.14
@@ -387,8 +385,8 @@ Cohesion: 0.40
 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 31 - "Store"
-Cohesion: 0.08
-Nodes (8): coverRelativePath(), coverSourceAddress(), displayChapter(), Store, scanSeries(), TestDisplayChapter(), Bookmark, ReaderSummary
+Cohesion: 0.09
+Nodes (5): coverRelativePath(), coverSourceAddress(), Store, scanSeries(), ReaderSummary
 
 ### Community 33 - "Go Testing Guide"
 Cohesion: 0.20
@@ -418,6 +416,10 @@ 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 - "Handler"
+Cohesion: 0.14
+Nodes (18): currentLib(), currentTab(), filterBookmarks(), Client, HandlerFunc, Request, ResponseWriter, Store (+10 more)
+
 ### Community 42 - "pgtest.go"
 Cohesion: 0.18
 Nodes (12): M, TestMain(), M, TestMain(), M, Main(), start(), URL() (+4 more)
@@ -534,6 +536,10 @@ Nodes (3): ADR-0005: On-demand browser sidecar, Constraints, Decision
 Cohesion: 0.48
 Nodes (6): T, TestCreateAndGetSession(), TestDeleteSessionIsPerReader(), TestDeleteSessionRevokes(), TestExpiredSessionIsGone(), TestGetSessionUnknownID()
 
+### Community 154 - "ADR-0011: Sightings — a Reader report defers a Poll where being wrong hurts only them"
+Cohesion: 0.33
+Nodes (5): ADR-0011: Sightings — a Reader report defers a Poll where being wrong hurts only them, Constraints preserved, Decision, Tradeoffs and rejections, Why
+
 ### Community 156 - "ResponseWriter"
 Cohesion: 0.18
 Nodes (13): AdminPatterns(), HandlerFunc, Request, ResponseWriter, Time, Handler, readerPathID(), since() (+5 more)
@@ -543,24 +549,24 @@ 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.
-- **150 thin communities (<3 nodes) omitted from report** — run `graphify query` to explore isolated nodes.
+- **151 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 `Open()` connect `CDP Browser Client` to `Cover Fetch Test Helpers`, `Series Acquisition Tests`, `Bookmarks API Tests`, `pgtest.go`, `Store Tests`, `Store`?**
+  _High betweenness centrality (0.060) - this node is a cross-community bridge._
+- **Why does `New()` connect `Series Acquisition Tests` to `Bookmarks API Tests`, `Cover & Acquire Internals`, `Handler`, `Session Middleware`, `CDP Browser Client`, `ResponseWriter`?**
   _High betweenness centrality (0.050) - this node is a cross-community bridge._
-- **Why does `New()` connect `Series Acquisition Tests` to `Bookmarks API Tests`, `Cover & Acquire Internals`, `Session Middleware`, `Web UI Handlers`, `CDP Browser Client`, `ResponseWriter`?**
-  _High betweenness centrality (0.048) - 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`, `ResponseWriter`?**
-  _High betweenness centrality (0.031) - this node is a cross-community bridge._
+  _High betweenness centrality (0.030) - this node is a cross-community bridge._
+- **Are the 25 inferred relationships involving `newTestStore()` (e.g. with `TestAcquireDoesNotBlockTheWrite()` and `TestAcquireFailureLeavesTheBookmarkIntact()`) actually correct?**
+  _`newTestStore()` has 25 INFERRED edges - model-reasoned connections that need verification._
 - **Are the 48 inferred relationships involving `testConfig()` (e.g. with `TestListRendersAcquiredCover()` and `TestPublicCoverNeverEchoesNonImage()`) actually correct?**
   _`testConfig()` has 48 INFERRED edges - model-reasoned connections that need verification._
-- **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._
 - **Are the 8 inferred relationships involving `newWebTestServer()` (e.g. with `TestListRendersAcquiredCover()` and `TestPublicCoverRejectsUnknownAddress()`) actually correct?**
   _`newWebTestServer()` has 8 INFERRED edges - model-reasoned connections that need verification._
 - **What connects `bookmarkmanager/backend`, `ctxKey`, `loginView` to the rest of the system?**
-  _552 weakly-connected nodes found - possible documentation gaps or missing edges._
+  _556 weakly-connected nodes found - possible documentation gaps or missing edges._

graphify-out/manifest.json

@@ -35,8 +35,8 @@
     "semantic_hash": "4a94ac85bad6bce330d085bcc0ae3ffd"
   },
   "userscript/manga-bookmark.user.js": {
-    "mtime": 1786499529.779988,
-    "ast_hash": "1f8bcddd3632d709f058a8401af8f127",
+    "mtime": 1786872888.3482232,
+    "ast_hash": "4e79684942234b26f4a1fb03fccd6d35",
     "semantic_hash": ""
   },
   ".agents/skills/find-skills/SKILL.md": {
@@ -225,8 +225,8 @@
     "semantic_hash": ""
   },
   "backend/api_test.go": {
-    "mtime": 1786863966.7056258,
-    "ast_hash": "0d443b4fe3c04ab057505d73b8a88d07",
+    "mtime": 1786868080.2317674,
+    "ast_hash": "b64372df5429fb14e48b37b3bab10402",
     "semantic_hash": ""
   },
   "backend/cover_test.go": {
@@ -235,9 +235,9 @@
     "semantic_hash": ""
   },
   "backend/internal/api/handlers.go": {
-    "mtime": 1786363889.552731,
-    "ast_hash": "59e6b8767ab19839bb8f82891a7e4616",
-    "semantic_hash": "59e6b8767ab19839bb8f82891a7e4616"
+    "mtime": 1786867745.788687,
+    "ast_hash": "ae4f3b961450f06a06e0632eb273a5b2",
+    "semantic_hash": ""
   },
   "backend/internal/httpmw/middleware.go": {
     "mtime": 1786216141.672644,
@@ -260,8 +260,8 @@
     "semantic_hash": ""
   },
   "backend/internal/latest/poller.go": {
-    "mtime": 1786865046.096795,
-    "ast_hash": "2bfb51177e3df474b80ea1b05523377e",
+    "mtime": 1786872774.641225,
+    "ast_hash": "5e55e2ac5cb7d347807754f92425d29b",
     "semantic_hash": ""
   },
   "backend/internal/latest/poller_test.go": {
@@ -270,8 +270,8 @@
     "semantic_hash": ""
   },
   "backend/internal/latest/sites.go": {
-    "mtime": 1786861012.026504,
-    "ast_hash": "9b90f9b710ccbd0d0a0a6a0dd721ff3c",
+    "mtime": 1786868771.0663204,
+    "ast_hash": "5786000dd0dfd5b4b3bd2b87b1fc100b",
     "semantic_hash": ""
   },
   "backend/internal/latest/sites_test.go": {
@@ -340,13 +340,13 @@
     "semantic_hash": "0b6764a0ee20f5cb7748eecd31a1d220"
   },
   "backend/internal/store/store.go": {
-    "mtime": 1786863704.5112119,
-    "ast_hash": "989629af18232e35b12f1eef2a8cb422",
+    "mtime": 1786868763.646761,
+    "ast_hash": "34f55617b7409f03f02e925bec92fac0",
     "semantic_hash": ""
   },
   "backend/internal/store/store_test.go": {
-    "mtime": 1786863712.075631,
-    "ast_hash": "e48f21e34238ba46874cc88cf96e022f",
+    "mtime": 1786867781.301985,
+    "ast_hash": "16f69d97eb63bcec7409294466642411",
     "semantic_hash": ""
   },
   "backend/internal/userscript/userscript.go": {
@@ -395,8 +395,8 @@
     "semantic_hash": "8008a187690764436540fab47ba0cfcc"
   },
   "userscript/novel-bookmark.user.js": {
-    "mtime": 1786499529.779988,
-    "ast_hash": "834effb0821f8d6c9f57f6554a5db462",
+    "mtime": 1786872902.809149,
+    "ast_hash": "36c81462919719f0e053ca5d633a243a",
     "semantic_hash": ""
   },
   "userscript/test/novel-logic.test.js": {
@@ -425,13 +425,13 @@
     "semantic_hash": "6c6f3e4c4c2f57867894280bce728c50"
   },
   "backend/AGENTS.md": {
-    "mtime": 1786865319.314815,
-    "ast_hash": "5bbabcd7dd425302cb0d989d8897baf6",
+    "mtime": 1786872951.3127444,
+    "ast_hash": "68bc86af9593adad1e37fa05188fe63e",
     "semantic_hash": ""
   },
   "backend/CLAUDE.md": {
-    "mtime": 1786865319.314815,
-    "ast_hash": "5bbabcd7dd425302cb0d989d8897baf6",
+    "mtime": 1786872951.3127444,
+    "ast_hash": "68bc86af9593adad1e37fa05188fe63e",
     "semantic_hash": ""
   },
   "backend/internal/web/templates/app.html": {
@@ -658,5 +658,20 @@
     "mtime": 1786865113.5362902,
     "ast_hash": "8b9f9c7a56e0ec3bf950aa70acd95e92",
     "semantic_hash": ""
+  },
+  "backend/internal/latest/sighting_test.go": {
+    "mtime": 1786868815.9760568,
+    "ast_hash": "3b1372bbeeb538b73f86f57da210b4cc",
+    "semantic_hash": ""
+  },
+  "backend/internal/store/migrations/0011_series_sightings.sql": {
+    "mtime": 1786867605.3728056,
+    "ast_hash": "d0ade928a6e951eb179e4d0255cca526",
+    "semantic_hash": ""
+  },
+  "docs/adr/0011-sighting-deferral-trust-model.md": {
+    "mtime": 1786872970.473592,
+    "ast_hash": "0b6ca704f62185c9d629320f2d8475b5",
+    "semantic_hash": ""
   }
 }

userscript/manga-bookmark.user.js

@@ -905,27 +905,37 @@
     }
   }
 
-  // Records the newest chapter a site has published. Silent: this fires from
+  // Reports the newest chapter a site has published. Silent: this fires from
   // page visits and background checks the user did not ask for, and it never
   // reorders the list — updated_at is a candidate the server discards unless
   // reading progress moved.
-  async function applyLatestChapterIfChanged(existing, latest) {
+  //
+  // An unchanged number is still sent. It is the read that lets the backend
+  // skip its own poll of this series (a Sighting, issue #103), so the common
+  // case — visiting a series with nothing new — is exactly the one worth
+  // reporting. Only the local write and the re-render are skipped.
+  async function reportLatestChapter(existing, latest) {
     if (!existing || !latest) return;
-    if (existing.latest_chapter_num === latest.num) return;
-    const bm = Object.assign({}, existing, {
-      latest_chapter: latest.label,
-      latest_chapter_num: latest.num,
-      updated_at: Date.now(),
-    });
-    upsertLocal(bm);
-    render();
+    const changed = existing.latest_chapter_num !== latest.num;
+    let bm = existing;
+    if (changed) {
+      bm = Object.assign({}, existing, {
+        latest_chapter: latest.label,
+        latest_chapter_num: latest.num,
+        updated_at: Date.now(),
+      });
+      upsertLocal(bm);
+      render();
+    }
     // A queued write owns this row; the drain sends latest_chapter
     // with it, carrying the correct bucket.
     if (queueGet(bm.key)) return;
     try {
       const saved = await apiPut(bm.key, bm);
-      upsertLocal(saved);
-      render();
+      if (changed) {
+        upsertLocal(saved);
+        render();
+      }
     } catch (e) {
       /* offline — the local cache still shows it, retried on a later visit */
     }
@@ -937,7 +947,7 @@
     if (p.type !== "series") return;
     const existing = state.byKey[keyOf(p)];
     if (!existing) return;
-    applyLatestChapterIfChanged(
+    reportLatestChapter(
       existing,
       computeLatestChapter(p.site, anchorsFromDocument(document), p.seriesId)
     );
@@ -977,7 +987,7 @@
           const html = await res.text();
           latest = computeLatestChapter(bm.site, anchorsFromHTML(html), bm.series_id);
         }
-        await applyLatestChapterIfChanged(state.byKey[bm.key] || bm, latest);
+        await reportLatestChapter(state.byKey[bm.key] || bm, latest);
       } catch (e) {
         /* offline or blocked — try again after the throttle window */
       }

userscript/novel-bookmark.user.js

@@ -809,27 +809,37 @@
     }
   }
 
-  // Records the newest chapter a site has published. Silent: this fires from
+  // Reports the newest chapter a site has published. Silent: this fires from
   // page visits and background checks the user did not ask for, and it never
   // reorders the list — updated_at is a candidate the server discards unless
   // reading progress moved.
-  async function applyLatestChapterIfChanged(existing, latest) {
+  //
+  // An unchanged number is still sent. It is the read that lets the backend
+  // skip its own poll of this series (a Sighting, issue #103), so the common
+  // case — visiting a series with nothing new — is exactly the one worth
+  // reporting. Only the local write and the re-render are skipped.
+  async function reportLatestChapter(existing, latest) {
     if (!existing || !latest) return;
-    if (existing.latest_chapter_num === latest.num) return;
-    const bm = Object.assign({}, existing, {
-      latest_chapter: latest.label,
-      latest_chapter_num: latest.num,
-      updated_at: Date.now(),
-    });
-    upsertLocal(bm);
-    render();
+    const changed = existing.latest_chapter_num !== latest.num;
+    let bm = existing;
+    if (changed) {
+      bm = Object.assign({}, existing, {
+        latest_chapter: latest.label,
+        latest_chapter_num: latest.num,
+        updated_at: Date.now(),
+      });
+      upsertLocal(bm);
+      render();
+    }
     // A queued write owns this row; the drain sends latest_chapter
     // with it, carrying the correct bucket.
     if (queueGet(bm.key)) return;
     try {
       const saved = await apiPut(bm.key, bm);
-      upsertLocal(saved);
-      render();
+      if (changed) {
+        upsertLocal(saved);
+        render();
+      }
     } catch (e) {
       /* offline — the local cache still shows it, retried on a later visit */
     }
@@ -841,7 +851,7 @@
     if (p.type !== "series") return;
     const existing = state.byKey[keyOf(p)];
     if (!existing) return;
-    applyLatestChapterIfChanged(
+    reportLatestChapter(
       existing,
       computeLatestChapter(p.site, anchorsFromDocument(document), p.seriesId)
     );
@@ -883,7 +893,7 @@
         if (!res.ok) continue;
         const html = await res.text();
         const latest = computeLatestChapter(bm.site, anchorsFromHTML(html), bm.series_id);
-        await applyLatestChapterIfChanged(state.byKey[bm.key] || bm, latest);
+        await reportLatestChapter(state.byKey[bm.key] || bm, latest);
       } catch (e) {
         /* offline or blocked — try again after the throttle window */
       }