Search bug fix 20260229

[paullizer]

• Workspace Search Deselection KeyError Fix
  • Fixed HTTP 500 error when deselecting the workspace search button after having a document selected. Users would get "Could not get a response. HTTP error! status: 500" in the chat interface.
  • Root Cause: When workspace search was deselected (hybrid_search_enabled = False), the user_metadata['workspace_search'] dictionary was never initialized. However, subsequent code for handling group scope or public workspace context attempted to access user_metadata['workspace_search']['group_name'] or other properties, causing a KeyError.
  • Error: KeyError: 'workspace_search' at lines 468, 479 in route_backend_chats.py when trying to set group_name or active_public_workspace_id.
  • Solution: Added defensive checks before accessing user_metadata['workspace_search']. If the key doesn't exist, initialize it with {'search_enabled': False} before attempting to set additional properties like group_name or workspace IDs.
  • Workaround: Clicking Home and then back to Chat worked because it triggered a page reload that reset the state properly.
  • (Ref: route_backend_chats.py, workspace search, metadata initialization, KeyError handling)