Admin dashboard: pages, Lane observability, poll pass log, per-Series intervention (#134) (#148)

Spec #134, all ten tickets. Closes #134.

## What ships

The admin surface becomes four bookmarkable addresses behind one nav row, and Lane observability stops dying with the process.

- **#138** `/admin` splits into Overview, Lanes, Readers, Series, each a real route with the active tab underlined.
- **#139** `poll_passes` and `poll_lanes` land as durable tables with their store surface.
- **#140** cross-Series admin read model, with the privacy boundary in the projection: the Reader id that raised a Latest Chapter never leaves the store package.
- **#141** the poller records exactly one pass row per exit, with a skip reason and outcome counts.
- **#142** Series list: eight hygiene filters, Site and Library narrowing, paging — all of it in the query string, so a filtered list is a bookmark.
- **#143** Overview: a three-state verdict line and a stats block where every non-zero figure links to the list that counts it.
- **#144** per-Series detail page, keyed by the `site:series_id` composite the rest of the system already uses.
- **#145** the Lanes page reads the database; the in-memory Lane state, `web.LaneReporter` and `latest.Status` are deleted.
- **#146** Forced Poll: *Check now* stamps `series.force_poll_at` and never commands the poller.
- **#147** pause and resume one Site's Lane, with a mandatory 1h/6h/24h expiry.

## Shape of the design

Two decisions carry the rest. **Commands go through the database, never at the poller**: both *Check now* and a Lane pause write a row the next pass reads, so they survive a restart and the whole surface stays testable with no poller running. And **pending is derived, never stored** — the request stamp being newer than the check stamp — which self-clears on the check stamp with no second write and no sweeper, because the check stamp is written before the fetch.

ADRs: `docs/adr/0012-persisted-lane-state.md`, `docs/adr/0013-commands-through-the-database.md`.

## Verification

`go test ./...` green on the merged base (`264839e`), all packages, Docker-backed. `gofmt -l` and `go vet` clean.

Every ticket was reviewed on both axes (`cr-spec` + `cr-standards`) before merge.

## Known, non-blocking

- **#143** the verdict ignores never-reported Lanes when other Lanes have reported, and the per-Site table lists Sites that have Series rather than the whole registry. The ticket prose asks for eight hygiene figures per Site; the design mock and the landed `.tbl.sites` grid both say six columns, and the mock won.
- **#146** two `SeriesPage` scans per press instead of a keyed read — `ponytail:`-commented in-tree with the upgrade path.
- **#147** a paused Site with no pass row yet renders no row and so no control, since the Lanes page lists Sites that have passed.
- **#141** a sibling browser Lane declining at the top of a pass records as `sidecar-down`. Specified deliberately; the later spec in this series settles it.

Reviewed-on: #148
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

backend/AGENTS.md

@@ -31,8 +31,7 @@ image, TLS terminated by the reverse proxy so the service listens plain `:8080`.
 store must have that `TestMain` or it has no database at all.
 
 ### Reader-owned store — `internal/store`, `internal/token`
-
-Four tables; shape is in the migrations, behaviour in `Store`'s methods.
+- The Reader-owned tables are `readers`, `bookmarks`, `series`, and `sessions`; auxiliary `covers`, `poll_lanes`, and `poll_passes` are also defined in the migrations.
 
 - **Credentials are derived, never stored.** `token.Token(TOKEN_KEY, discord_id, epoch)`
   is an HMAC; only its SHA-256 reaches `readers.token_sha256`. So install URLs
@@ -135,7 +134,7 @@ unchanged read is exactly the Sighting worth deferring a Poll on.
   rest.
 
 **Refusals and browser loss are Lane-local.** Two `errChallengeHeld` in a pass
-stop that Site for `refuseBackoff` while other Lanes continue. An
+stop that Site for `RefuseBackoff` while other Lanes continue. An
 `errBrowserInterrupted` (remote Chrome restarted) sets a shared Poller flag so
 the *other* browser Lanes skip their passes for the same window — otherwise a
 restarting Chrome stamps one Series per Lane per pass, burning rests on
@@ -253,16 +252,18 @@ keep warning to reinstall on all devices.
   (`view.Owner = readerID == h.store.OwnerID()`): it gates a link, not an
   endpoint, so it is a rendering decision a registration-time wrapper cannot
   express. Do not "unify" it into the gate.
-- Lane figures come through the `web.LaneReporter` seam
-  (`latest.Poller.LaneStatus`), never a table. `main.newRouter` takes the
-  reporter as an interface and converts a nil `*Poller` to a nil interface — a
-  typed nil would make the page claim a poller exists.
+- The Lanes page reads the pass log, never a running poller: `lanesView()` in
+  `admin_lanes.go` projects `store.LatestLanePasses()` and
+  `store.LanePassOutcomes()` (ADR-0012), so a restart answers the instant the
+  database is up. Browser configuration is a config fact and reachability is
+  derived from recent browser-Site passes inside `latest.RefuseBackoff` — no
+  reporter interface exists to fake.
 - A pass that returns before computing figures (refusal backoff, sidecar down)
   carries the previous pass's numbers forward rather than recording zeroes.
 - **`Checked` next to `Due` is what separates a stopped Lane from a quiet one**,
   so neither may be dropped from the row.
 - Due-without-Checked is **not** by itself a stall: a browser Lane under both
-  wake thresholds sets `LaneState.Asleep` and renders "browser asleep", and
-  never counts toward `Attention`. That is the commonest healthy state for
-  kagane, comix and novelfull, so spending the stall mark on it would train the
-  owner to ignore the mark that matters.
+  wake thresholds records its pass with the `SkipAsleep` skip and renders
+  "browser asleep", and that never counts toward `Attention`. It is the
+  commonest healthy state for kagane, comix and novelfull, so spending the
+  stall mark on it would train the owner to ignore the mark that matters.