fix(#252): harden block gating per Gemini review

Guard _sendMessageDirect too (automatic retries route there without
passing sendMessage, so a pre-block message kept retrying post-block),
log both connector drops instead of returning silently, and surface a
blocked-contact snackbar on the manual retry and reaction paths.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/connector/meshcore_connector.dart

@@ -1235,6 +1235,15 @@ class MeshCoreConnector extends ChangeNotifier {
     int timestampSeconds,
   ) async {
     if (!isConnected || text.isEmpty) return;
+    // Automatic retries route here without passing sendMessage — stop them
+    // too once the contact is blocked (#252).
+    if (_blockService?.isBlocked(contact.publicKeyHex) ?? false) {
+      appLogger.info(
+        'Dropped outgoing DM retry to blocked contact',
+        tag: 'Connector',
+      );
+      return;
+    }
     try {
       await _waitForRadioQuiet(lastInboundRxTime: _lastContactMsgRxTime);
       final outboundText = prepareContactOutboundText(contact, text);
@@ -3080,7 +3089,13 @@ class MeshCoreConnector extends ChangeNotifier {
     if (!isConnected || text.isEmpty) return;
     // Outgoing DMs (incl. reactions and retries) to a blocked contact are
     // dropped — mirrors the incoming DM-drop so a block is symmetric (#252).
-    if (_blockService?.isBlocked(contact.publicKeyHex) ?? false) return;
+    if (_blockService?.isBlocked(contact.publicKeyHex) ?? false) {
+      appLogger.info(
+        'Dropped outgoing DM to blocked contact',
+        tag: 'Connector',
+      );
+      return;
+    }
 
     // Check if this is a reaction - apply locally with pending status and route through retry service
     final reactionInfo = ReactionHelper.parseReaction(text);

lib/screens/chat_screen.dart

@@ -1789,6 +1789,13 @@ class _ChatScreenState extends State<ChatScreen> {
 
   void _retryMessage(Message message) {
     final connector = Provider.of<MeshCoreConnector>(context, listen: false);
+    if (context.read<BlockService>().isBlocked(widget.contact.publicKeyHex)) {
+      showDismissibleSnackBar(
+        context,
+        content: Text(context.l10n.block_composerNotice),
+      );
+      return;
+    }
     // Retry using the contact's current path override setting
     connector.sendMessage(_resolveContact(connector), message.text);
     showDismissibleSnackBar(
@@ -1811,6 +1818,13 @@ class _ChatScreenState extends State<ChatScreen> {
 
   void _sendReaction(Message message, Contact senderContact, String emoji) {
     final connector = context.read<MeshCoreConnector>();
+    if (context.read<BlockService>().isBlocked(widget.contact.publicKeyHex)) {
+      showDismissibleSnackBar(
+        context,
+        content: Text(context.l10n.block_composerNotice),
+      );
+      return;
+    }
     final emojiIndex = ReactionHelper.emojiToIndex(emoji);
     if (emojiIndex == null) return; // Unknown emoji, skip
     final timestampSecs = message.timestamp.millisecondsSinceEpoch ~/ 1000;