fix: Bug - Add logout in mobile version of settings, allow clearing data on android

Expose settings logout on mobile where the title bar is hidden, and enable
Capacitor data settings with storage visibility and local erase/sign-out.

Co-authored-by: Cursor <cursoragent@cursor.com>

agents-docs/features/authentication.md

@@ -12,6 +12,12 @@ Session-token authentication for the signaling server and product client.
 | Electron Local API | Separate in-memory bearer tokens | Proxies login to allowed signaling servers only |
 | Product client local DB | OS user account | SQLite and attachments are plaintext at rest |
 
+## Client logout
+
+- Desktop: title-bar menu **Logout** (`UserLogoutService`).
+- Mobile / all platforms: settings modal footer **Logout** (`data-testid="settings-logout-button"`) — required because the title bar is hidden on mobile breakpoints.
+- Logout disconnects realtime sessions, clears the persisted current-user id, resets NgRx room/user/message state, and navigates to `/login`.
+
 ## Login / register response
 
 ```json