Crash on New User Signup (Friends List 404)

### 🐛 Describe the bug

When a new user signs up and logs in for the first time, the application throws an unhandled exception and immediately redirects back to the Welcome/Login screen instead of proceeding to the Home screen.

The Cause: Upon login, the FriendsController initializes and attempts to fetch the user's "Friends List" document from the Appwrite database. For a brand new user, this document does not exist yet. Appwrite returns a 404 Document Not Found error.

The current code treats this 404 as a critical failure instead of a valid "empty" state. This exception causes the user profile initialization to fail, triggering the catch block in auth_state_controller.dart, which forces a redirect back to the WelcomeScreen. It also triggers a secondary No Overlay widget found error because it attempts to show an error Snackbar during the screen transition.

lib/controllers/friends_controller.dart. The getFriendsList() method does not handle the 404 case for new users.

Steps to Reproduce:

Run the app on a fresh install (or clear app data).

specific user signup flow to create a new account.

Observe the crash/redirect immediately after clicking "Sign Up".

E/flutter (19429): [ERROR:flutter/runtime/dart_vm_initializer.cc(40)] Unhandled Exception: AppwriteException: document_not_found, Document with the requested ID could not be found. (404)
E/flutter (19429): #0 ClientMixin.prepareResponse (package:appwrite/src/client_mixin.dart:95:9)
E/flutter (19429): #1 ClientIO.call (package:appwrite/src/client_io.dart:415:14)
E/flutter (19429):
E/flutter (19429): #2 Databases.getDocument (package:appwrite/services/databases.dart:205:17)
E/flutter (19429):
E/flutter (19429): #3 FriendsController.getFriendsList (package:resonate/controllers/friends_controller.dart:98:21)
E/flutter (19429):
E/flutter (19429): #4 FriendsController.onInit (package:resonate/controllers/friends_controller.dart:40:5)