🧭 fix: Robust 404 Conversation Not Found Redirect (#11853)

* fix: route to new conversation when conversation not found

* Addressed PR feedback

* fix: Robust 404 conversation redirect handling

- Extract `isNotFoundError` utility to `utils/errors.ts` so axios stays
  contained in one place rather than leaking into route/query layers
- Add `initialConvoQuery.isError` to the useEffect dependency array so
  the redirect actually fires when the 404 response arrives after other
  deps have already settled (was the root cause of the blank screen)
- Show a warning toast so users understand why they were redirected
- Add `com_ui_conversation_not_found` i18n key

* fix: Enhance error handling in getResponseStatus function

- Update the getResponseStatus function to ensure it correctly returns the status from error objects only if the status is a number. This improves robustness in error handling by preventing potential type issues.

* fix: Improve conversation not found handling in ChatRoute

- Enhance error handling when a conversation is not found by checking additional conditions before showing a warning toast.
- Update the newConversation function to include model data and preset options, improving user experience during error scenarios.

* fix: Log error details for conversation not found in ChatRoute

- Added logging for the initial conversation query error when a conversation is not found, improving debugging capabilities and error tracking in the ChatRoute component.

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Co-authored-by: Dan Lew <daniel@mightyacorn.com>

client/src/locales/en/translation.json

@@ -842,6 +842,7 @@
   "com_ui_controls": "Controls",
   "com_ui_conversation": "conversation",
   "com_ui_conversation_label": "{{title}} conversation",
+  "com_ui_conversation_not_found": "Conversation not found",
   "com_ui_conversations": "conversations",
   "com_ui_convo_archived": "Conversation archived",
   "com_ui_convo_delete_error": "Failed to delete conversation",