Failed to reconnect between networks

# VPN service fails to reconnect after switching network type (Wi-Fi ↔ mobile)

**Device:** Pixel 8 (stock), Android 17 CP2A.260805.005
**Build:** main branch, 2026-09-13 23:20 MSK

## Steps to reproduce

1. Start VPN service — works fine.
2. Switch network type (Wi-Fi ↔ mobile/rmnet), either direction.

## Expected behavior

Service automatically reconnects on the new network.

## Actual behavior

Service fails to reconnect and stays broken until manually stopped/started.

## Log evidence

The attached logcat shows an exception right at the moment of the auto-restart attempt after the network switch:

```
java.lang.RuntimeException: A WebView method was called on thread
'DefaultDispatcher-worker-3'. All WebView methods must be called on the
same thread.
StartCore-Manager: Failed to reload core: ...
```

The stack trace points to this call chain:

```
NetworkMonitor.scheduleHandover
-> CoreServiceManager.reloadCore
-> CoreServiceManager.launchCore
-> DialerWebviewService.stop
-> WebView.stopLoading
```

## Suspected cause

It looks like `DialerWebviewService.stop()` (`DialerWebviewService.kt`) calls a WebView method off the main thread, causing `reloadCore()` to throw and the core to never restart on the new network.

I'm not 100% sure — I only traced this from the log/stack trace, not the actual source. Would appreciate it if a maintainer could check that path (`DialerWebviewService.stop` / `CoreServiceManager.kt`) — it may need `runOnUiThread` / `Dispatchers.Main` instead of calling WebView directly from a coroutine.

## Attachments

- Full logcat

[v2ray.md](https://github.com/user-attachments/files/32170607/v2ray.md)

Start with NetworkMonitor.scheduleHandover and trace the call chain through CoreServiceManager.kt and DialerWebviewService.kt. Reproduce a Wi-Fi/mobile network switch while inspecting logcat, then verify the service reconnects without the reported WebView thread exception or failed core reload.

Scritto dal modello di indicizzazione a partire dal testo della issue.