feat: Enhance message handling with recipient public key and delivery status for improved retry support

lib/screens/messages_tab.dart

@@ -170,7 +170,7 @@ class _MessagesTabState extends State<MessagesTab> {
         final devicePublicKey = connectionProvider.deviceInfo.publicKey;
         final senderPublicKeyPrefix = devicePublicKey?.sublist(0, 6);
 
-        // Create sent message object
+        // Create sent message object with recipient public key for retry support
         final sentMessage = Message(
           id: messageId,
           messageType: MessageType.contact,
@@ -181,6 +181,7 @@ class _MessagesTabState extends State<MessagesTab> {
           text: fullMessage,
           receivedAt: DateTime.now(),
           deliveryStatus: MessageDeliveryStatus.sending,
+          recipientPublicKey: roomPublicKey, // Store recipient for retry
           // SAR marker data is automatically added by SarMessageParser.enhanceMessage in MessagesProvider
         );
 
@@ -408,15 +409,42 @@ class _MessageBubble extends StatelessWidget {
 
       // Resend the message
       if (failedMessage.messageType == MessageType.contact) {
-        // Direct message retry - NOT YET IMPLEMENTED
-        // Would need to look up contact's full public key by senderKeyShort
-        messagesProvider.markMessageFailed(retryMessageId);
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('Direct message retry not yet implemented'),
-            backgroundColor: Colors.orange,
-          ),
+        // Direct message retry (for SAR markers sent to rooms)
+        if (failedMessage.recipientPublicKey == null) {
+          messagesProvider.markMessageFailed(retryMessageId);
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('Cannot retry: recipient information missing'),
+              backgroundColor: Colors.red,
+            ),
+          );
+          return;
+        }
+
+        // Resend to the same room
+        final sentSuccessfully = await connectionProvider.sendTextMessage(
+          contactPublicKey: failedMessage.recipientPublicKey!,
+          text: failedMessage.text,
+          messageId: retryMessageId,
         );
+
+        if (!sentSuccessfully) {
+          messagesProvider.markMessageFailed(retryMessageId);
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('Failed to resend message'),
+              backgroundColor: Colors.red,
+            ),
+          );
+        } else {
+          ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(
+              content: Text('Retrying message...'),
+              backgroundColor: Colors.orange,
+              duration: Duration(seconds: 2),
+            ),
+          );
+        }
       } else if (failedMessage.messageType == MessageType.channel) {
         // Channel message retry
         await connectionProvider.sendChannelMessage(

lib/services/message_storage_service.dart

@@ -120,6 +120,14 @@ class MessageStorageService {
       'sarGpsLon': message.sarGpsCoordinates?.longitude,
       'receivedAtMillis': message.receivedAt.millisecondsSinceEpoch,
       'senderName': message.senderName,
+      'deliveryStatus': message.deliveryStatus.name,
+      'expectedAckTag': message.expectedAckTag,
+      'suggestedTimeoutMs': message.suggestedTimeoutMs,
+      'roundTripTimeMs': message.roundTripTimeMs,
+      'deliveredAtMillis': message.deliveredAt?.millisecondsSinceEpoch,
+      'recipientPublicKey': message.recipientPublicKey != null
+          ? base64Encode(message.recipientPublicKey!)
+          : null,
     };
   }
 
@@ -155,6 +163,23 @@ class MessageStorageService {
         receivedAt: DateTime.fromMillisecondsSinceEpoch(
             json['receivedAtMillis'] as int),
         senderName: json['senderName'] as String?,
+        deliveryStatus: json['deliveryStatus'] != null
+            ? MessageDeliveryStatus.values.firstWhere(
+                (e) => e.name == json['deliveryStatus'],
+                orElse: () => MessageDeliveryStatus.received,
+              )
+            : MessageDeliveryStatus.received,
+        expectedAckTag: json['expectedAckTag'] as int?,
+        suggestedTimeoutMs: json['suggestedTimeoutMs'] as int?,
+        roundTripTimeMs: json['roundTripTimeMs'] as int?,
+        deliveredAt: json['deliveredAtMillis'] != null
+            ? DateTime.fromMillisecondsSinceEpoch(
+                json['deliveredAtMillis'] as int)
+            : null,
+        recipientPublicKey: json['recipientPublicKey'] != null
+            ? Uint8List.fromList(
+                base64Decode(json['recipientPublicKey'] as String))
+            : null,
       );
     } catch (e) {
       print('❌ [MessageStorage] Error parsing message from JSON: $e');