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

packages/commons_core/lib/src/social/nostr/relay_pool.dart

@@ -26,19 +26,32 @@ class RelayPool implements NostrChannel {
   /// Number of relays currently connected (for diagnostics/tests).
   int get relayCount => _connections.length;
 
-  /// Connects to each of [relayUrls], skipping any that fail. Throws
-  /// [StateError] only when NONE are reachable, so the caller can treat that as
-  /// "offline".
+  /// Connects to each of [relayUrls], skipping any that fail or take longer
+  /// than [connectTimeout] — a relay on a silently-filtering network would
+  /// otherwise hang the whole pool for minutes. Throws [StateError] only when
+  /// NONE are reachable, so the caller can treat that as "offline".
   static Future<RelayPool> connect(
     List<String> relayUrls, {
     required NostrIdentity identity,
+    Duration connectTimeout = const Duration(seconds: 10),
   }) async {
     final connections = <NostrConnection>[];
     await Future.wait(
       relayUrls.map((url) async {
         try {
+          final attempt = NostrConnection.connect(url, identity: identity);
           connections.add(
-            await NostrConnection.connect(url, identity: identity),
+            await attempt.timeout(
+              connectTimeout,
+              onTimeout: () {
+                // Abandon the hung attempt; if it ever completes, close it so
+                // the socket doesn't leak.
+                unawaited(
+                  attempt.then((c) => c.close()).catchError((_) {}),
+                );
+                throw TimeoutException('relay connect timed out', connectTimeout);
+              },
+            ),
           );
         } catch (_) {
           // Unreachable relay — skip it, keep the rest.

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(