Owner Finish control on the Series detail page: confirm-gated finish, instant un-finish (#158)

backend/internal/store/admin.go

@@ -42,7 +42,7 @@ type SeriesFilter struct {
 // and only the anonymous boolean in raisedByReaderAnswer crosses it.
 const adminSeriesColumns = `s.site, s.series_id, s.title, s.series_url, s.cover_address,
 	s.kind, s.latest_chapter, s.latest_chapter_num, s.latest_checked_at, s.force_poll_at,
-	s.latest_corrected_at`
+	s.latest_corrected_at, s.finished_at`
 
 // raisedByReaderAnswer answers "did a Reader's report set this number" without
 // naming which Reader. Kept apart from adminSeriesColumns so the column list —
@@ -80,7 +80,9 @@ type AdminSeries struct {
 	LatestCorrectedAt int64
 	ReaderCount       int
 	RaisedByReader    bool // a Reader's report set LatestChapterNum
-
+	// FinishedAt is the owner's finish stamp: unix ms, zero while the Series is
+	// not finished — the same shape as the Correction stamp, and its own undo.
+	FinishedAt int64
 }
 
 // SeriesPage is one page of the owner's filtered Series list plus the count
@@ -196,7 +198,7 @@ func (s *Store) SeriesPage(f SeriesFilter) (SeriesPage, error) {
 		`+where+`
 		GROUP BY s.site, s.series_id, s.title, s.series_url, s.cover_address,
 		         s.kind, s.latest_chapter, s.latest_chapter_num, s.latest_checked_at,
-		         s.force_poll_at, s.latest_corrected_at, s.latest_raised_by
+		         s.force_poll_at, s.latest_corrected_at, s.finished_at, s.latest_raised_by
 		`+having+`
 		ORDER BY s.latest_checked_at, s.site, s.series_id
 		LIMIT $`+strconv.Itoa(base+1)+` OFFSET $`+strconv.Itoa(base+2), args...)
@@ -271,7 +273,7 @@ func scanAdminSeries(scan func(...any) error) (AdminSeries, int, error) {
 	if err := scan(
 		&a.Site, &a.SeriesID, &a.Title, &a.SeriesURL, &a.CoverAddress,
 		&a.Kind, &a.LatestChapter, &latestChapterNum, &a.LatestCheckedAt,
-		&a.ForcePollAt, &a.LatestCorrectedAt,
+		&a.ForcePollAt, &a.LatestCorrectedAt, &a.FinishedAt,
 		&a.RaisedByReader, &a.ReaderCount, &total,
 	); err != nil {
 		return AdminSeries{}, 0, err