fix: Fix list_sessions()

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>

llama_stack/providers/inline/agents/meta_reference/persistence.py

@@ -183,21 +183,39 @@ class AgentPersistence:
         )
         return int(value) if value else None
 
-    async def list_sessions(self) -> list[Session]:
-        values = await self.kvstore.values_in_range(
-            start_key=f"session:{self.agent_id}:",
-            end_key=f"session:{self.agent_id}:\xff\xff\xff\xff",
-        )
+    async def _get_sessions_from_keys(self, keys: list[str]) -> list[Session]:
+        """
+        Helper method to filter session keys and retrieve session objects.
+
+        Args:
+            keys: List of keys from the KV store
+
+        Returns:
+            List of parsed Session objects
+        """
+        # filter session metadata to relevant keys (3 parts: agent_id, session_id, and turn_id)
+        session_keys = [key for key in keys if len(key.split(":")) == 3]
+
         sessions = []
-        for value in values:
+        for key in session_keys:
             try:
-                session_info = Session(**json.loads(value))
-                sessions.append(session_info)
+                value = await self.kvstore.get(key)
+                if value:
+                    session_info = Session(**json.loads(value))
+                    sessions.append(session_info)
             except Exception as e:
                 log.error(f"Error parsing session info: {e}")
                 continue
         return sessions
 
+    async def list_sessions(self) -> list[Session]:
+        keys = await self.kvstore.keys_in_range(
+            start_key=f"session:{self.agent_id}:",
+            end_key=f"session:{self.agent_id}:\xff\xff\xff\xff",
+        )
+        sessions = await self._get_sessions_from_keys(keys)
+        return sessions
+
     async def delete_session_turns(self, session_id: str) -> None:
         """Delete all turns and their associated data for a session.