refactor: update handlers to use unified search endpoint

- Update SearchMediaItems handler to use SearchService
- Add autocomplete detection for field value queries (author=value, genre=value, etc.)
- Add handleFieldValuesSearch method for dropdown population
- Add sort parameter extraction with default "title ASC"
- Remove deprecated ListMediaItemsFiltered handler
- Remove deprecated /api/media-items/filtered route registration
- Update frontend.go to use SearchMediaItemsUnified instead of ListMediaItemsFiltered
- Fix parameter passing (empty filters use Valid:true with empty values, not Valid:false)
- Add SearchQuery, IsExactSearch, SearchPattern parameters for query parsing

Handler is now a thin wrapper that extracts params and delegates to service layer.

internal/handlers/media.go

@@ -704,69 +704,6 @@ func (mh *MediaHandler) GetMediaItem(c *echo.Context) error {
 	})
 }
 
-// ListMediaItemsFiltered handles GET /api/media-items/filtered
-func (mh *MediaHandler) ListMediaItemsFiltered(c *echo.Context) error {
-	userID := c.Get("user_id").(string)
-	libraryID := c.QueryParam("library_id")
-	sort := c.QueryParam("sort")
-	limit, _ := strconv.Atoi(c.QueryParam("limit"))
-	offset, _ := strconv.Atoi(c.QueryParam("offset"))
-
-	authorFilter := c.QueryParam("author_filter")
-	seriesFilter := c.QueryParam("series_filter")
-	genreFilter := c.QueryParam("genre_filter")
-	languageFilter := c.QueryParam("language_filter")
-	yearMin, _ := strconv.Atoi(c.QueryParam("year_min"))
-	yearMax, _ := strconv.Atoi(c.QueryParam("year_max"))
-	hasCover, _ := strconv.ParseBool(c.QueryParam("has_cover"))
-
-	if limit == 0 {
-		limit = 50
-	}
-
-	if offset < 0 {
-		offset = 0
-	}
-
-	if sort == "" {
-		sort = "created_at DESC"
-	}
-
-	if limit > maxPaginationLimit {
-		limit = maxPaginationLimit
-	}
-
-	libUUID, err := uuid.Parse(libraryID)
-	if err != nil {
-		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid library id"})
-	}
-
-	userUUID, err := uuid.Parse(userID)
-	if err != nil {
-		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid user id"})
-	}
-
-	items, err := mh.db.ListMediaItemsFiltered(c.Request().Context(), database.ListMediaItemsFilteredParams{
-		LibraryID:      pgtype.UUID{Bytes: libUUID, Valid: true},
-		UserID:         pgtype.UUID{Bytes: userUUID, Valid: true},
-		AuthorFilter:   pgtype.Text{String: authorFilter, Valid: true},
-		SeriesFilter:   pgtype.Text{String: seriesFilter, Valid: true},
-		GenreFilter:    pgtype.Text{String: genreFilter, Valid: true},
-		LanguageFilter: pgtype.Text{String: languageFilter, Valid: true},
-		YearMin:        pgtype.Int4{Int32: int32(yearMin), Valid: true},
-		YearMax:        pgtype.Int4{Int32: int32(yearMax), Valid: true},
-		HasCover:       pgtype.Bool{Bool: hasCover, Valid: true},
-		Sort:           pgtype.Text{String: sort, Valid: true},
-		Limit:          pgtype.Int4{Int32: int32(limit), Valid: true},
-		Offset:         pgtype.Int4{Int32: int32(offset), Valid: true},
-	})
-	if err != nil {
-		return c.JSON(http.StatusInternalServerError, map[string]string{"error": err.Error()})
-	}
-
-	return c.JSON(http.StatusOK, map[string]interface{}{"data": items})
-}
-
 // CreateMediaRating handles POST /api/media-items/:id/rating
 func (mh *MediaHandler) CreateMediaRating(c *echo.Context) error {
 	userID := c.Get("user_id").(string)
@@ -1471,6 +1408,12 @@ func (mh *MediaHandler) SearchMediaItems(c *echo.Context) error {
 	yearMax, _ := strconv.Atoi(c.QueryParam("year_max"))
 	hasCover := c.QueryParam("has_cover") == "true"
 
+	// Extract sort parameter
+	sortParam := c.QueryParam("sort")
+	if sortParam == "" {
+		sortParam = "title ASC" // Default sort
+	}
+
 	// Build search params
 	params := services.SearchParams{
 		UserID:         userID.ID,
@@ -1483,6 +1426,7 @@ func (mh *MediaHandler) SearchMediaItems(c *echo.Context) error {
 		YearMin:        yearMin,
 		YearMax:        yearMax,
 		HasCover:       hasCover,
+		Sort:           sortParam,
 		Limit:          limit,
 		Offset:         offset,
 	}

internal/router/frontend.go

@@ -175,7 +175,7 @@ func registerFrontendRoutes(cfg *Config) {
 		}
 
 		// Fetch first page of books for SSR
-		var books []database.ListMediaItemsFilteredRow
+		var books []database.SearchMediaItemsUnifiedRow
 		var bookInfoList []handlers.BookInfo
 		totalCount := 0
 		limit := 50
@@ -196,23 +196,26 @@ func registerFrontendRoutes(cfg *Config) {
 					}
 				}
 
-				books, err = cfg.Queries.ListMediaItemsFiltered(c.Request().Context(), database.ListMediaItemsFilteredParams{
+				books, err = cfg.Queries.SearchMediaItemsUnified(c.Request().Context(), database.SearchMediaItemsUnifiedParams{
 					LibraryID:      pgtype.UUID{Bytes: libUUID, Valid: true},
 					UserID:         pgtype.UUID{Bytes: userUUID, Valid: true},
-					AuthorFilter:   pgtype.Text{String: "", Valid: false},
+					AuthorFilter:   pgtype.Text{String: "", Valid: true},  // Changed: Valid=true for empty string
-					SeriesFilter:   pgtype.Text{String: "", Valid: false},
+					SeriesFilter:   pgtype.Text{String: "", Valid: true},  // Changed
-					GenreFilter:    pgtype.Text{String: "", Valid: false},
+					GenreFilter:    pgtype.Text{String: "", Valid: true},  // Changed
-					LanguageFilter: pgtype.Text{String: "", Valid: false},
+					LanguageFilter: pgtype.Text{String: "", Valid: true},  // Changed
-					YearMin:        pgtype.Int4{Valid: false},
+					YearMin:        pgtype.Int4{Int32: 0, Valid: true},    // Changed: use 0 as default
-					YearMax:        pgtype.Int4{Valid: false},
+					YearMax:        pgtype.Int4{Int32: 0, Valid: true},    // Changed
-					HasCover:       pgtype.Bool{Valid: false},
+					HasCover:       pgtype.Bool{Bool: false, Valid: true}, // Changed
+					SearchQuery:    pgtype.Text{String: "", Valid: true},  // NEW: Required
+					IsExactSearch:  pgtype.Bool{Bool: false, Valid: true}, // NEW: Required
+					SearchPattern:  pgtype.Text{Valid: false},             // NEW: Empty for no exact search
 					Sort:           pgtype.Text{String: "created_at DESC", Valid: true},
 					Limit:          pgtype.Int4{Int32: int32(limit), Valid: true},
 					Offset:         pgtype.Int4{Int32: int32(offset), Valid: true},
 				})
 
 				if err != nil {
-					log.Printf("ListMediaItemsFiltered failed: %v", err)
+					log.Printf("SearchMediaItemsUnified failed: %v", err)
 					// Continue without books - will show empty state
 				} else {
 					// Convert database rows to BookInfo structs (matching BuildSections pattern)

internal/router/media.go

@@ -14,7 +14,6 @@ func registerMediaRoutes(cfg *Config) {
 
 	// Media item routes (all authenticated users)
 	protected.GET("/media-items", cfg.MediaHandler.ListMediaItems)
-	protected.GET("/media-items/filtered", cfg.MediaHandler.ListMediaItemsFiltered)
 	protected.GET("/media-items/:id", cfg.MediaHandler.GetMediaItem)
 
 	// Media rating routes (all authenticated users)