fix: get_status returns actual configured WG address instead of hardcoded default

The address field in get_status() was hardcoded to SERVER_ADDRESS
('10.0.0.1/24') regardless of what wg0.conf contains, so instances
with a non-default subnet (e.g. pic1 at 10.0.1.1/24) always reported
the wrong server IP to callers such as the e2e WG conftest fixture.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/wireguard_manager.py

@@ -1094,12 +1094,14 @@ class WireGuardManager(BaseServiceManager):
                 capture_output=True, text=True, timeout=5,
             )
             running = 'cell-wireguard' in result.stdout
+            configured_addr = self._get_configured_address()
             return {
                 'running': running,
                 'status': 'online' if running else 'offline',
                 'interface': 'wg0',
                 'listen_port': self._get_configured_port(),
-                'ip_info': {'address': SERVER_ADDRESS} if running else {},
+                'address': configured_addr if running else None,
+                'ip_info': {'address': configured_addr} if running else {},
                 'peers_count': len(self.get_peers()),
                 'timestamp': datetime.utcnow().isoformat(),
             }