Sync button remains disabled after switching from offline to online mode

Nobody has claimed this yet.

**Description**
When switching from offline to online mode while the app remains open, the sync button remains disabled until the user reopens the app or navigates away from and back to the project. This creates an unnecessary workflow disruption as users expect the sync functionality to become available automatically once network connectivity is restored.

**Environment**
Staging

**Application (+ app version, build, operating system)**
Android app version: 2025.3.1
Android version: 14

**Steps to reproduce**
1. Open the Mergin Maps mobile app
2. Open a specific project
3. Put the device in airplane mode or disable network connection
4. Close and kill the application
5. Reopen the app
6. Verify that the sync button is disabled (**expected behavior???**)
7. Re-enable network connection while keeping the app open and in the same project
8. Observe that the sync button remains disabled even though the device is online

**Actual results**
The sync button remains disabled after regaining network connectivity unless the user closes and reopens the app or navigates away from and back to the project.

**Expected results**
The sync button should automatically become enabled when the device regains network connectivity, without requiring the user to close and reopen the app or navigate away from the project.

**Screenshots or logs**
N/A

*Conclusion*
*Created by GitHub Copilot and supervised by a human test analyst.*

Reproduce the issue on Android 14 with app version 2025.3.1, starting with the offline-to-online transition while the same project remains open. Trace how connectivity changes affect the project’s sync button; done means the button enables automatically after connectivity returns without reopening the app or navigating away.

Written by the indexing model from the issue text.