Spec #136: Finished belongs to the Series — owner-owned poll gate, Lifecycle bucket dropped (#163)

Closes #136.

Spec #136 end to end: `finished` becomes a fact about the Series, written only by the owner, and the reader-facing Lifecycle bucket is gone.

## What landed

- **#157** — `series.finished_at bigint NOT NULL DEFAULT 0` plus the migration whose statement order is load-bearing (seed from the buckets, then flip them); both Lane queries lose the `HAVING COUNT(*) FILTER (WHERE b.status <> 'finished')` clause and gate on `finished_at = 0` instead, with the due-query/eligible-count force asymmetry kept deliberate and commented; `StatusFinished`, its API special-case 400, the web tab and the templates' Finished bucket deleted.
- **#158** — owner Finish control on the Series detail page: confirm-gated finish, instant un-finish, admin accent (never ember, nothing is destroyed), `Store.SetSeriesFinished`, the two routes behind the owner gate, and the state displayed on the list row without offering the control there.
- **#160** — reader side: derived `finished` bool on the flat Bookmark (`s.finished_at > 0`), rendered as a text-only label in both userscripts and on the web card; read-only inbound by omission from `Upsert`'s explicit `series` column list, same mechanism that already protects `cover`.
- **#161** — glossary and the stale Reader-count divergence note catch up.
- **#159** — `finished` joins the admin filter vocabulary (predicate `finished_at > 0`, label `Finished`, own aggregate count, figure last in the stats block as informational); the four clock-driven hygiene predicates (stale, never-checked, no-cover, no-chapter) exclude finished Series while unpollable, orphan and sighting-raised deliberately do not.

## Verification

`go vet ./...` and `go test ./...` green on the merged branch (Docker-backed, throwaway `postgres:17-alpine` per package). Each ticket also passed a two-axis review (spec + standards) on its own branch before merge.

Reviewed-on: #163
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

backend/internal/web/admin_series.go

@@ -20,10 +20,10 @@ import (
 // the wrong page. The store does not export it (#140).
 const seriesPageSize = 50
 
-// seriesFilterLabels names every hygiene filter for the Series list select,
-// keyed by the wire constant the URL carries. The render order is
-// seriesFilterOrder; the labels are read by later admin tickets too, so the
-// map and the constants cannot drift apart.
+// seriesFilterLabels names every Series filter for the list select, keyed by
+// the wire constant the URL carries. The render order is seriesFilterOrder;
+// the labels are read by later admin tickets too, so the map and the
+// constants cannot drift apart.
 var seriesFilterLabels = map[string]string{
 	store.SeriesFilterAll:          "All series",
 	store.SeriesFilterNoURL:        "No series URL",
@@ -33,10 +33,13 @@ var seriesFilterLabels = map[string]string{
 	store.SeriesFilterStale:        "Not checked in 12h",
 	store.SeriesFilterNoCover:      "No cover",
 	store.SeriesFilterReaderReport: "Latest from a Reader",
+	store.SeriesFilterFinished:     "Finished",
 }
 
 // seriesFilterOrder is the select's render order: All first, then the
-// permanent repairs, then the fixable ones (issue #140).
+// permanent repairs, then the fixable ones (issue #140). Finished rides the
+// tail, last — deliberate, not a repair — and the Overview's stats block
+// renders the same tail, which is what sits the finished figure last there.
 var seriesFilterOrder = []string{
 	store.SeriesFilterAll,
 	store.SeriesFilterNoURL,
@@ -46,6 +49,7 @@ var seriesFilterOrder = []string{
 	store.SeriesFilterStale,
 	store.SeriesFilterNoCover,
 	store.SeriesFilterReaderReport,
+	store.SeriesFilterFinished,
 }
 
 // seriesListView is the Series list page's data. The template renders strings
@@ -110,6 +114,11 @@ type seriesRowView struct {
 	// raced answer: the row stays and says a fresh Bookmark caught the press.
 	CanRemove      bool
 	RemovalRefused bool
+	// Finished is the row's display of the owner's finish stamp: the list row
+	// shows the state and never offers the control — that lives on the detail
+	// page, where a press that retires a Series from the Lane is on purpose
+	// and confirm-gated (issue #158).
+	Finished bool
 }
 
 // adminSeries renders the filterable, bookmarkable Series list: filter, Site,
@@ -182,6 +191,96 @@ func (h *Handler) adminSeriesPoll(w http.ResponseWriter, r *http.Request) {
 	h.render(w, http.StatusOK, "series-row", seriesRow(a, band, time.Now()))
 }
 
+// adminSeriesFinish is the owner's Finish control: it stamps the Series'
+// finished_at and answers with the freshly rendered meta fragment, so the
+// "finished <age> ago" line describes the state after the press. The Lane's
+// next pass reads the stamp and stops polling the Series (issue #157). The
+// owner gate is the route's, not this handler's; the body is capped like the
+// API path caps its bodies; the key is validated here — a malformed key is a
+// 400 and an unknown one a 404.
+func (h *Handler) adminSeriesFinish(w http.ResponseWriter, r *http.Request) {
+	site, seriesID, ok := strings.Cut(r.PathValue("key"), ":")
+	if !ok || site == "" || seriesID == "" {
+		http.Error(w, "bad series key", http.StatusBadRequest)
+		return
+	}
+	r.Body = http.MaxBytesReader(w, r.Body, 1<<16)
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, "invalid form", http.StatusBadRequest)
+		return
+	}
+	if _, found, err := h.adminSeriesByKey(site, seriesID); err != nil {
+		log.Printf("series finish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	} else if !found {
+		http.NotFound(w, r)
+		return
+	}
+	if err := h.store.SetSeriesFinished(site, seriesID, time.Now().UnixMilli()); err != nil {
+		log.Printf("series finish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	// Re-read after the stamp: the answer must describe the state after the
+	// press, so the line reads "finished just now". The control's one caller
+	// is the detail page, which swaps the meta fragment in place.
+	a, found, err := h.adminSeriesByKey(site, seriesID)
+	if err != nil {
+		log.Printf("series finish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	if !found {
+		http.NotFound(w, r)
+		return
+	}
+	h.render(w, http.StatusOK, "series-detail-meta", h.seriesDetailView(a))
+}
+
+// adminSeriesUnfinish is the reversal of the Finish control: it clears the
+// stamp (writes zero) and answers with the freshly rendered meta fragment, so
+// the Series is back in the Lane's queue from its next pass. Reversal, so it
+// fires instantly with no confirm row (issue #158).
+func (h *Handler) adminSeriesUnfinish(w http.ResponseWriter, r *http.Request) {
+	site, seriesID, ok := strings.Cut(r.PathValue("key"), ":")
+	if !ok || site == "" || seriesID == "" {
+		http.Error(w, "bad series key", http.StatusBadRequest)
+		return
+	}
+	r.Body = http.MaxBytesReader(w, r.Body, 1<<16)
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, "invalid form", http.StatusBadRequest)
+		return
+	}
+	if _, found, err := h.adminSeriesByKey(site, seriesID); err != nil {
+		log.Printf("series unfinish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	} else if !found {
+		http.NotFound(w, r)
+		return
+	}
+	if err := h.store.SetSeriesFinished(site, seriesID, 0); err != nil {
+		log.Printf("series unfinish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	// Re-read after the write: the answer must describe the state after the
+	// press, so the fragment no longer carries the finished line.
+	a, found, err := h.adminSeriesByKey(site, seriesID)
+	if err != nil {
+		log.Printf("series unfinish %s: %v", site+":"+seriesID, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	if !found {
+		http.NotFound(w, r)
+		return
+	}
+	h.render(w, http.StatusOK, "series-detail-meta", h.seriesDetailView(a))
+}
+
 // adminSeriesCorrectLatest is the Latest Chapter correction: the owner types
 // one number and the Series' Latest Chapter becomes it, stamped as a
 // Correction. The number must be a finite float greater than zero — a
@@ -516,9 +615,9 @@ func (h *Handler) seriesListView(r *http.Request) (seriesListView, error) {
 	return view, nil
 }
 
-// seriesFilterOptions renders every hygiene filter with its library-wide
-// count, one SeriesShapes pass per filter summed in Go — the shipped surface
-// offers eight grouped passes, not a single stats query (#140). The counts
+// seriesFilterOptions renders every filter with its library-wide count, one
+// SeriesShapes pass per filter summed in Go — the shipped surface offers nine
+// grouped passes, not a single stats query (#140). The counts
 // are library-wide because the select sits next to the Site narrowing and
 // must not shift as the owner narrows the list itself. Cutoff travels with
 // the stale filter, or its count would always be zero.
@@ -572,6 +671,7 @@ func seriesRow(a store.AdminSeries, i int, now time.Time) seriesRowView {
 		CanRemove: a.ReaderCount == 0,
 		Pending:   pending,
 		Requested: requested,
+		Finished:  a.FinishedAt > 0,
 	}
 	if a.LatestChapterNum != nil {
 		row.Ch = strconv.FormatFloat(*a.LatestChapterNum, 'f', -1, 64)