feat(memory): add session-based chat history and user metadata retrieval

- Add ChatSessionCache to manage chat history per session
- Add SEARCH_USER_METADATA cypher query for retrieving user entity metadata
- Add "str" mode support to StructResponse for raw text extraction
- Add content_str field to MemorySearchResult for pre-formatted content
- Fix sandbox URL by removing hardcoded port
- Add description field to entity search results
- Remove history from UserInput schema, use session_id instead

api/app/core/workflow/nodes/code/node.py

@@ -132,7 +132,7 @@ class CodeNode(BaseNode):
 
         async with httpx.AsyncClient(timeout=60) as client:
             response = await client.post(
-                f"{settings.SANDBOX_URL}:8194/v1/sandbox/run",
+                f"{settings.SANDBOX_URL}/v1/sandbox/run",
                 headers={
                     "x-api-key": 'redbear-sandbox'
                 },

api/app/core/workflow/nodes/memory/node.py

@@ -40,6 +40,7 @@ class MemoryReadNode(BaseNode):
                 end_user_id=end_user_id,
                 user_rag_memory_id=state["user_rag_memory_id"],
             )
+            # TODO: Historical Messages -> Used to refer to coreference resolution
             search_result = await memory_service.read(
                 self._render_template(self.typed_config.message, variable_pool),
                 search_switch=SearchStrategy(self.typed_config.search_switch)