fix(dashboard): Prevent fatal error when database connection is unavailable (#37576)

superset/explorables/base.py

@@ -106,6 +106,18 @@ class Explorable(Protocol):
     # Identity & Metadata
     # =========================================================================
 
+    @property
+    def id(self) -> int | str:
+        """
+        Primary key identifier for this explorable.
+
+        Used for database lookups such as row-level security filter resolution.
+        Must be accessible without triggering expensive operations like
+        database engine connections.
+
+        :return: Primary key (typically int, but may be str for some implementations)
+        """
+
     @property
     def uid(self) -> str:
         """