Implement collection item reordering with bulk operations and persistent HTML attributes

- Add bulk reorder API endpoint (PUT /api/collections/{id}/reorder) with atomic transactions
- Replace individual position updates with efficient bulk operations in frontend
- Implement unified ID generation and proper data-item-id injection during enhancement
- Fix collection item position persistence through content edit cycles
- Add optimistic UI with rollback capability for better user experience
- Update sqlc queries to include last_edited_by fields in position updates
- Remove obsolete data-content-type attributes and unify naming conventions

internal/db/database.go

@@ -95,6 +95,16 @@ func (db *Database) GetDBType() string {
 	return db.dbType
 }
 
+// GetSQLiteDB returns the underlying SQLite database connection
+func (db *Database) GetSQLiteDB() *sql.DB {
+	return db.conn
+}
+
+// GetPostgreSQLDB returns the underlying PostgreSQL database connection
+func (db *Database) GetPostgreSQLDB() *sql.DB {
+	return db.conn
+}
+
 // initializeSQLiteSchema sets up the SQLite database schema
 func (db *Database) initializeSQLiteSchema() error {
 	ctx := context.Background()