fix(social): cap relay connect with a timeout so one hung relay can't stall the pool

packages/commons_core/test/social/relay_pool_test.dart

@@ -1,3 +1,4 @@
+import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:commons_core/commons_core.dart';
@@ -58,6 +59,38 @@ void main() {
     await r1.stop();
   });
 
+  test('a hung relay cannot stall the pool past the connect timeout', () async {
+    // A server that accepts TCP but never answers the WebSocket handshake —
+    // the shape of a silently-filtered network, where connect hangs for minutes.
+    final hang = await ServerSocket.bind(InternetAddress.loopbackIPv4, 0);
+    final held = <Socket>[];
+    hang.listen(held.add);
+    final r1 = await MiniRelay.start();
+    final alice = await idFor(5);
+
+    final sw = Stopwatch()..start();
+    final pool = await RelayPool.connect(
+      [r1.url, 'ws://127.0.0.1:${hang.port}'],
+      identity: alice,
+      connectTimeout: const Duration(milliseconds: 500),
+    );
+    sw.stop();
+
+    expect(pool.relayCount, 1, reason: 'the live relay is kept');
+    expect(
+      sw.elapsed,
+      lessThan(const Duration(seconds: 5)),
+      reason: 'the hung relay must not stall the whole pool',
+    );
+
+    await pool.close();
+    for (final s in held) {
+      s.destroy();
+    }
+    await hang.close();
+    await r1.stop();
+  });
+
   test('throws when no relay is reachable (caller treats as offline)', () async {
     final alice = await idFor(4);
     expect(