android: home phase 1 - header, quick actions, pause, problem cards

- Connect tab gets the Shield-S header and, while connected, three quick
  actions: pause, switch server, "site not loading?" (route check).
- Pause VPN for 5/15/30/60 min (PauseManager + PauseReceiver): disconnects
  like a manual stop and reconnects on an alarm; auto-connect waits, any
  connect request cancels the pause. Home shows a countdown, "turn on now"
  and "+15 minutes".
- Connection errors become plain-language cards with one fixing action:
  no internet (tracked via a non-VPN network callback), server not
  responding (with the retry countdown and "other server"), server not
  found, sign-in rejected, server not verified, generic failure.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/frontends/android/app/src/main/AndroidManifest.xml

@@ -293,6 +293,10 @@
         <receiver
             android:name=".logic.WatchdogReceiver"
             android:exported="false" />
+        <!-- ends a "pause VPN for N minutes" and reconnects the paused profile -->
+        <receiver
+            android:name=".logic.PauseReceiver"
+            android:exported="false" />
         <!-- runs after the app has updated itself (the system kills the
              process during the install): cleans up and lets auto-connect
              restore the VPN -->