feat(audiobooks): migration 153 + BookmarkStore.CountByUser extension

Migration 153 backs the upcoming smart-collections surface.
BookmarkStore.CountByUser returns per-item counts in one SQL pass —
used by the smart-collection items evaluator to hydrate the
bookmark_count personalized rule without N+1 queries.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/audiobooks/abs/bookmarks.go

@@ -20,6 +20,11 @@ type BookmarkStore interface {
 	// Returns nil when no row matched — DELETE is idempotent (a UX
 	// convenience, not a 404 surface). See spec §6.
 	Delete(ctx context.Context, userID, profileID, itemID string, timeSeconds float64) error
+	// CountByUser returns a map of library_item_id -> bookmark count
+	// for the given (user, profile). Empty map (never nil) when none.
+	// Used by the smart-collection items evaluator to hydrate the
+	// `bookmark_count` personalized rule in one SQL pass.
+	CountByUser(ctx context.Context, userID, profileID string) (map[string]int, error)
 }
 
 // Bookmark is the in-memory representation of an abs_bookmarks row as

internal/audiobooks/abs/bookmarks_handler_test.go

@@ -94,6 +94,31 @@ func (m *memBookmarkStore) Delete(_ context.Context, userID, profileID, itemID s
 	return nil
 }
 
+func (m *memBookmarkStore) CountByUser(_ context.Context, userID, profileID string) (map[string]int, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	out := map[string]int{}
+	prefix := userID + "|" + profileID + "|"
+	for k := range m.rows {
+		if strings.HasPrefix(k, prefix) {
+			rest := k[len(prefix):]
+			sep := -1
+			for i, c := range rest {
+				if c == '|' {
+					sep = i
+					break
+				}
+			}
+			if sep < 0 {
+				continue
+			}
+			itemID := rest[:sep]
+			out[itemID]++
+		}
+	}
+	return out, nil
+}
+
 func formatSeq(n int) string {
 	b, _ := json.Marshal(n)
 	return string(b)

internal/audiobooks/abs_bookmark_store.go

@@ -122,3 +122,39 @@ func (s *ABSBookmarkStore) Delete(ctx context.Context, userID, profileID, itemID
 	}
 	return nil
 }
+
+// CountByUser returns a map of library_item_id -> bookmark count for
+// the given (user, profile). One SQL query; used by the
+// smart-collection items evaluator for batch hydration.
+func (s *ABSBookmarkStore) CountByUser(ctx context.Context, userID, profileID string) (map[string]int, error) {
+	uid, err := strconv.Atoi(userID)
+	if err != nil {
+		return nil, fmt.Errorf("abs_bookmark_store: invalid user id %q: %w", userID, err)
+	}
+	rows, err := s.Pool.Query(ctx, `
+		SELECT library_item_id, COUNT(*)
+		FROM abs_bookmarks
+		WHERE user_id = $1
+		  AND COALESCE(profile_id, '00000000-0000-0000-0000-000000000000'::uuid)
+		      = COALESCE($2::uuid, '00000000-0000-0000-0000-000000000000'::uuid)
+		GROUP BY library_item_id`,
+		uid, profileArg(profileID),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("abs_bookmark_store: count-by-user: %w", err)
+	}
+	defer rows.Close()
+	out := map[string]int{}
+	for rows.Next() {
+		var itemID string
+		var count int
+		if err := rows.Scan(&itemID, &count); err != nil {
+			return nil, fmt.Errorf("abs_bookmark_store: count-by-user scan: %w", err)
+		}
+		out[itemID] = count
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("abs_bookmark_store: count-by-user rows: %w", err)
+	}
+	return out, nil
+}

migrations/153_abs_smart_collections.down.sql

@@ -0,0 +1,2 @@
+DROP INDEX IF EXISTS public.abs_smart_collections_user_profile_idx;
+DROP TABLE IF EXISTS public.abs_smart_collections;

migrations/153_abs_smart_collections.up.sql

@@ -0,0 +1,25 @@
+-- Smart Collections — rule-based dynamic groupings of audiobooks.
+-- The query_def JSONB column stores the DSL tree (see
+-- internal/audiobooks/smartcoll/query.go). Profile-scoped per the
+-- established convention; is_public allows cross-user reads with
+-- personalization stripped at eval time.
+
+CREATE TABLE IF NOT EXISTS public.abs_smart_collections (
+    id          text PRIMARY KEY,
+    user_id     integer NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
+    profile_id  uuid,
+    name        text NOT NULL,
+    description text NOT NULL DEFAULT '',
+    color       text NOT NULL DEFAULT '',
+    is_public   boolean NOT NULL DEFAULT false,
+    is_pinned   boolean NOT NULL DEFAULT false,
+    query_def   jsonb NOT NULL DEFAULT '{}'::jsonb,
+    created_at  timestamptz NOT NULL DEFAULT now(),
+    updated_at  timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS abs_smart_collections_user_profile_idx
+    ON public.abs_smart_collections (
+        user_id,
+        COALESCE(profile_id, '00000000-0000-0000-0000-000000000000'::uuid)
+    );