fix: improve type safety in media item search queries

- Change library_id parameter from interface{} to pgtype.UUID
- Add explicit UUID type casting in SQL queries
- Fix SearchMediaItemsParams to use strongly-typed UUID
- Prevents potential type assertion errors and improves type safety
- Ensures proper NULL handling for optional library_id filter

internal/database/queries.sql.go

@@ -6931,7 +6931,7 @@ JOIN libraries l ON mi.library_id = l.id
 JOIN library_types lt ON l.library_type_id = lt.id
 LEFT JOIN library_visibility lv ON l.id = lv.library_id AND lv.user_id = $1
  WHERE COALESCE(lv.is_visible, true) = true
-   AND ($2 IS NULL OR mi.library_id = $2)
+   AND ($2::uuid IS NULL OR mi.library_id = $2::uuid)
    AND (
        mi.title ILIKE $3 OR
        mi.author ILIKE $3 OR
@@ -6953,7 +6953,7 @@ LIMIT $5 OFFSET $4
 
 type SearchMediaItemsParams struct {
 	UserID        pgtype.UUID `db:"user_id" json:"user_id"`
-	LibraryID     interface{} `db:"library_id" json:"library_id"`
+	LibraryID     pgtype.UUID `db:"library_id" json:"library_id"`
 	SearchPattern pgtype.Text `db:"search_pattern" json:"search_pattern"`
 	Offset        pgtype.Int4 `db:"offset" json:"offset"`
 	Limit         pgtype.Int4 `db:"limit" json:"limit"`