Fix review findings R1–R3 on Regular grounding and name folding

R1: Migration 0010 now writes revision 0 into every ground_dinner job
payload that has none. Jobs queued before the upgrade carry only
dinner_id, so the boot cleanup, which matches a pending dinner to its job
by revision, failed those dinners as interrupted while their jobs were
still queued. The migration runs before the job runner starts. A new test
migrates a database to 0009, adds a pending Regular with a legacy queued
job, upgrades and boots, and checks the dinner stays pending and is then
grounded.

R2: Archiving a dinner, or renaming a pending one, now cancels the
grounding of any ground_dinner job running for it at an older revision,
so no further search, page fetch, photo download or model call is made.
The job is registered before it reads the dinner, so an archive or rename
committed after that read always finds it. A stopped job succeeds and
reports the dinner's current grounding status. The archive and rename
tests now check that the job ends while its search is still held, with
no page fetched and no model call for the stale name.

R3: gen_folds.py writes web/src/dinners/letterFolds.json from the same
table as folds_table.go, and names.ts folds through it instead of a
hand-copied subset. names.ts also lowercases letter by letter, as Go's
strings.ToLower does, rather than by context. TestLetterFoldsMatchPWA
fails when the two tables differ. The shared cases add "Ƈhili", "Ꞔarbanzo
Stew" and "ΜΟΥΣΑΚΑΣ" (final sigma).

Maestro task 5037ff86-181d-448e-927b-c2fd2258a25d.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/dinners/grounding.go

@@ -104,8 +104,14 @@ func (r groundResult) PublicJSON() ([]byte, error) { return json.Marshal(r) }
 // either result is recorded only while the dinner is still unarchived,
 // pending and at p.Revision: a dinner grounded by hand meanwhile is left as
 // it is, and one renamed or archived meanwhile is left pending — for the
-// job its rename enqueued, or for none.
+// job its rename enqueued, or for none. Archiving or renaming the dinner
+// stops the grounding where it is, so no further search, fetch, photo
+// download or model call is made for it.
 func (s *Service) runGroundJob(ctx context.Context, p GroundJob, _ func(groundResult) error) (groundResult, error) {
+	// Tracked before the dinner is read: an archive or rename committed
+	// after the read finds this job to stop.
+	groundCtx, done := s.trackGrounding(ctx, p.DinnerID, p.Revision)
+	defer done()
 	row, err := db.New(s.st.Reader).GetDinner(ctx, p.DinnerID)
 	if err != nil {
 		return groundResult{}, fmt.Errorf("dinners: ground: read %s: %w", p.DinnerID, err)
@@ -116,9 +122,12 @@ func (s *Service) runGroundJob(ctx context.Context, p GroundJob, _ func(groundRe
 
 	var gr recipes.Grounded
 	if row.RecipeUrl.Valid {
-		gr, err = s.grounder.GroundURL(ctx, row.RecipeUrl.String)
+		gr, err = s.grounder.GroundURL(groundCtx, row.RecipeUrl.String)
 	} else {
-		gr, err = s.grounder.Ground(ctx, row.Name, row.Name)
+		gr, err = s.grounder.Ground(groundCtx, row.Name, row.Name)
+	}
+	if err != nil && ctx.Err() == nil && errors.Is(context.Cause(groundCtx), errGroundingStopped) {
+		return s.currentGrounding(ctx, row.ID)
 	}
 	if err != nil {
 		reason := reasonFor(err, row.RecipeUrl.Valid)
@@ -157,15 +166,67 @@ func (s *Service) runGroundJob(ctx context.Context, p GroundJob, _ func(groundRe
 		return groundResult{}, fmt.Errorf("dinners: ground: record %s: %w", row.ID, err)
 	}
 	if n == 0 {
-		cur, err := db.New(s.st.Reader).GetDinner(ctx, row.ID)
-		if err != nil {
-			return groundResult{}, fmt.Errorf("dinners: ground: read %s: %w", row.ID, err)
-		}
-		return groundResult{DinnerID: cur.ID, GroundingStatus: cur.GroundingStatus}, nil
+		return s.currentGrounding(ctx, row.ID)
 	}
 	return groundResult{DinnerID: row.ID, GroundingStatus: GroundingGrounded}, nil
 }
 
+// currentGrounding is the KindGroundDinner result of a job that did not
+// ground dinner id: the grounding status the dinner has now.
+func (s *Service) currentGrounding(ctx context.Context, id string) (groundResult, error) {
+	cur, err := db.New(s.st.Reader).GetDinner(ctx, id)
+	if err != nil {
+		return groundResult{}, fmt.Errorf("dinners: ground: read %s: %w", id, err)
+	}
+	return groundResult{DinnerID: cur.ID, GroundingStatus: cur.GroundingStatus}, nil
+}
+
+// errGroundingStopped is the cause a running KindGroundDinner job's
+// grounding is cancelled with when its dinner is archived or renamed.
+var errGroundingStopped = errors.New("dinners: grounding stopped: dinner archived or renamed")
+
+// runningGrounding is a KindGroundDinner job running for a dinner at
+// revision, with the cancel of its grounding.
+type runningGrounding struct {
+	revision int64
+	cancel   context.CancelCauseFunc
+}
+
+// trackGrounding returns a context for grounding dinnerID at revision that
+// stopGroundings cancels, and the func to call when the job ends.
+func (s *Service) trackGrounding(ctx context.Context, dinnerID string, revision int64) (context.Context, func()) {
+	groundCtx, cancel := context.WithCancelCause(ctx)
+	r := &runningGrounding{revision: revision, cancel: cancel}
+	s.groundingsMu.Lock()
+	if s.groundings[dinnerID] == nil {
+		s.groundings[dinnerID] = make(map[*runningGrounding]struct{})
+	}
+	s.groundings[dinnerID][r] = struct{}{}
+	s.groundingsMu.Unlock()
+	return groundCtx, func() {
+		s.groundingsMu.Lock()
+		delete(s.groundings[dinnerID], r)
+		if len(s.groundings[dinnerID]) == 0 {
+			delete(s.groundings, dinnerID)
+		}
+		s.groundingsMu.Unlock()
+		cancel(nil)
+	}
+}
+
+// stopGroundings cancels, with errGroundingStopped, the grounding of every
+// KindGroundDinner job running for dinnerID at a revision below below. Call
+// it once the change that makes those jobs stale is committed.
+func (s *Service) stopGroundings(dinnerID string, below int64) {
+	s.groundingsMu.Lock()
+	defer s.groundingsMu.Unlock()
+	for r := range s.groundings[dinnerID] {
+		if r.revision < below {
+			r.cancel(errGroundingStopped)
+		}
+	}
+}
+
 // FailInterruptedGroundings fails, with ReasonInterrupted, every dinner
 // still pending whose KindGroundDinner job is no longer queued or running:
 // a previous process stopped before enqueuing the job or before its