fix: repair notification system (broken type assertion + wrong PocketBase filter quotes)

- Add bookstore.NotificationStore interface and wire it directly to *storage.Store
  in Dependencies, bypassing the Asynq wrapper that caused Producer.(*storage.Store)
  to fail with a 500 on every notification endpoint when Redis is configured
- Replace s.deps.Producer.(*storage.Store) type assertion in all 5 notification
  handlers with s.deps.NotificationStore (nil-safe, always works)
- Fix PocketBase filter single-quote bug in ListNotifications, ClearAllNotifications,
  and MarkAllNotificationsRead (PocketBase requires double quotes for string values)

backend/cmd/backend/main.go

@@ -199,6 +199,7 @@ func run() error {
 			BookWriter:        store,
 			AIJobStore:        store,
 			BookAdminStore:    store,
+			NotificationStore: store,
 			Log:               log,
 		},
 	)

backend/internal/backend/handlers_notifications.go

@@ -3,8 +3,6 @@ package backend
 import (
 	"encoding/json"
 	"net/http"
-
-	"github.com/libnovel/backend/internal/storage"
 )
 
 // handleDismissNotification handles DELETE /api/notifications/{id}.
@@ -14,12 +12,11 @@ func (s *Server) handleDismissNotification(w http.ResponseWriter, r *http.Reques
 		jsonError(w, http.StatusBadRequest, "notification id required")
 		return
 	}
-	store, ok := s.deps.Producer.(*storage.Store)
+	if s.deps.NotificationStore == nil {
-	if !ok {
+		jsonError(w, http.StatusServiceUnavailable, "notification store not configured")
-		jsonError(w, http.StatusInternalServerError, "storage not available")
 		return
 	}
-	if err := store.DeleteNotification(r.Context(), id); err != nil {
+	if err := s.deps.NotificationStore.DeleteNotification(r.Context(), id); err != nil {
 		jsonError(w, http.StatusInternalServerError, "dismiss notification: "+err.Error())
 		return
 	}
@@ -33,12 +30,11 @@ func (s *Server) handleClearAllNotifications(w http.ResponseWriter, r *http.Requ
 		jsonError(w, http.StatusBadRequest, "user_id required")
 		return
 	}
-	store, ok := s.deps.Producer.(*storage.Store)
+	if s.deps.NotificationStore == nil {
-	if !ok {
+		jsonError(w, http.StatusServiceUnavailable, "notification store not configured")
-		jsonError(w, http.StatusInternalServerError, "storage not available")
 		return
 	}
-	if err := store.ClearAllNotifications(r.Context(), userID); err != nil {
+	if err := s.deps.NotificationStore.ClearAllNotifications(r.Context(), userID); err != nil {
 		jsonError(w, http.StatusInternalServerError, "clear notifications: "+err.Error())
 		return
 	}
@@ -52,12 +48,11 @@ func (s *Server) handleMarkAllNotificationsRead(w http.ResponseWriter, r *http.R
 		jsonError(w, http.StatusBadRequest, "user_id required")
 		return
 	}
-	store, ok := s.deps.Producer.(*storage.Store)
+	if s.deps.NotificationStore == nil {
-	if !ok {
+		jsonError(w, http.StatusServiceUnavailable, "notification store not configured")
-		jsonError(w, http.StatusInternalServerError, "storage not available")
 		return
 	}
-	if err := store.MarkAllNotificationsRead(r.Context(), userID); err != nil {
+	if err := s.deps.NotificationStore.MarkAllNotificationsRead(r.Context(), userID); err != nil {
 		jsonError(w, http.StatusInternalServerError, "mark all read: "+err.Error())
 		return
 	}
@@ -80,13 +75,12 @@ func (s *Server) handleListNotifications(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	store, ok := s.deps.Producer.(*storage.Store)
+	if s.deps.NotificationStore == nil {
-	if !ok {
+		jsonError(w, http.StatusServiceUnavailable, "notification store not configured")
-		jsonError(w, http.StatusInternalServerError, "storage not available")
 		return
 	}
 
-	items, err := store.ListNotifications(r.Context(), userID, 50)
+	items, err := s.deps.NotificationStore.ListNotifications(r.Context(), userID, 50)
 	if err != nil {
 		jsonError(w, http.StatusInternalServerError, "list notifications: "+err.Error())
 		return
@@ -97,7 +91,7 @@ func (s *Server) handleListNotifications(w http.ResponseWriter, r *http.Request)
 	for _, item := range items {
 		b, _ := json.Marshal(item)
 		var n notification
-		json.Unmarshal(b, &n)
+		json.Unmarshal(b, &n) //nolint:errcheck
 		notifications = append(notifications, n)
 	}
 
@@ -111,16 +105,15 @@ func (s *Server) handleMarkNotificationRead(w http.ResponseWriter, r *http.Reque
 		return
 	}
 
-	store, ok := s.deps.Producer.(*storage.Store)
+	if s.deps.NotificationStore == nil {
-	if !ok {
+		jsonError(w, http.StatusServiceUnavailable, "notification store not configured")
-		jsonError(w, http.StatusInternalServerError, "storage not available")
 		return
 	}
 
-	if err := store.MarkNotificationRead(r.Context(), id); err != nil {
+	if err := s.deps.NotificationStore.MarkNotificationRead(r.Context(), id); err != nil {
 		jsonError(w, http.StatusInternalServerError, "mark read: "+err.Error())
 		return
 	}
 
 	writeJSON(w, 0, map[string]any{"success": true})
-}
+}

backend/internal/backend/server.go

@@ -94,6 +94,10 @@ type Dependencies struct {
 	// BookAdminStore provides admin-only operations: archive, unarchive, hard-delete.
 	// If nil, the admin book management endpoints return 503.
 	BookAdminStore bookstore.BookAdminStore
+	// NotificationStore manages per-user in-app notifications.
+	// Always wired directly to *storage.Store (not the Asynq wrapper) so
+	// notification endpoints work regardless of whether Redis/Asynq is in use.
+	NotificationStore bookstore.NotificationStore
 	// Log is the structured logger.
 	Log *slog.Logger
 }

backend/internal/bookstore/bookstore.go

@@ -247,3 +247,14 @@ type ImportFileStore interface {
 	// GetImportChapters retrieves the pre-parsed chapters JSON.
 	GetImportChapters(ctx context.Context, key string) ([]byte, error)
 }
+
+// NotificationStore manages per-user in-app notifications.
+// Always wired directly to the concrete *storage.Store so it works
+// regardless of whether the Asynq task-queue wrapper is in use.
+type NotificationStore interface {
+	ListNotifications(ctx context.Context, userID string, limit int) ([]map[string]any, error)
+	MarkNotificationRead(ctx context.Context, id string) error
+	MarkAllNotificationsRead(ctx context.Context, userID string) error
+	DeleteNotification(ctx context.Context, id string) error
+	ClearAllNotifications(ctx context.Context, userID string) error
+}

backend/internal/storage/store.go

@@ -773,7 +773,7 @@ func (s *Store) CreateNotification(ctx context.Context, userID, title, message,
 
 // ListNotifications returns notifications for a user.
 func (s *Store) ListNotifications(ctx context.Context, userID string, limit int) ([]map[string]any, error) {
-	filter := fmt.Sprintf("user_id='%s'", userID)
+	filter := fmt.Sprintf(`user_id="%s"`, userID)
 	items, err := s.pb.listAll(ctx, "notifications", filter, "-created")
 	if err != nil {
 		return nil, err
@@ -805,7 +805,7 @@ func (s *Store) DeleteNotification(ctx context.Context, id string) error {
 
 // ClearAllNotifications deletes all notifications for a user.
 func (s *Store) ClearAllNotifications(ctx context.Context, userID string) error {
-	filter := fmt.Sprintf("user_id='%s'", userID)
+	filter := fmt.Sprintf(`user_id="%s"`, userID)
 	items, err := s.pb.listAll(ctx, "notifications", filter, "")
 	if err != nil {
 		return fmt.Errorf("ClearAllNotifications list: %w", err)
@@ -823,7 +823,7 @@ func (s *Store) ClearAllNotifications(ctx context.Context, userID string) error
 
 // MarkAllNotificationsRead marks all notifications for a user as read.
 func (s *Store) MarkAllNotificationsRead(ctx context.Context, userID string) error {
-	filter := fmt.Sprintf("user_id='%s'&&read=false", userID)
+	filter := fmt.Sprintf(`user_id="%s"&&read=false`, userID)
 	items, err := s.pb.listAll(ctx, "notifications", filter, "")
 	if err != nil {
 		return fmt.Errorf("MarkAllNotificationsRead list: %w", err)