Add retry for failed media packets

lib/screens/messages_tab.dart

@@ -457,6 +457,7 @@ class _MessagesTabState extends State<MessagesTab> {
         grayscale: grayscale,
       );
       if (result == null) {
+        if (!mounted) return;
         ToastLogger.error(context, 'Image compression failed');
         return;
       }
@@ -487,6 +488,7 @@ class _MessagesTabState extends State<MessagesTab> {
       );
 
       if (fragments.isEmpty) {
+        if (!mounted) return;
         ToastLogger.error(context, 'Image fragmentation failed');
         return;
       }
@@ -494,6 +496,7 @@ class _MessagesTabState extends State<MessagesTab> {
       // Build envelope.
       final deviceKey = connectionProvider.deviceInfo.publicKey;
       if (deviceKey == null || deviceKey.length < 6) {
+        if (!mounted) return;
         ToastLogger.error(context, 'Device key unavailable');
         return;
       }
@@ -513,6 +516,8 @@ class _MessagesTabState extends State<MessagesTab> {
         timestampSec: DateTime.now().millisecondsSinceEpoch ~/ 1000,
       );
 
+      if (!mounted) return;
+
       // Cache for deferred serving.
       final imageProvider = context.read<ip.ImageProvider>();
       imageProvider.cacheOutgoingSession(sessionId, fragments, envelope);
@@ -555,6 +560,7 @@ class _MessagesTabState extends State<MessagesTab> {
         );
         if (!sent) {
           messagesProvider.markMessageFailed(msgId);
+          if (!mounted) return;
           ToastLogger.error(context, 'Failed to announce image');
         }
       }
@@ -566,6 +572,7 @@ class _MessagesTabState extends State<MessagesTab> {
       );
     } catch (e, st) {
       debugPrint('❌ [Image] _pickAndSendImage: $e\n$st');
+      if (!mounted) return;
       ToastLogger.error(context, 'Image send failed');
     } finally {
       if (mounted) setState(() => _isSendingImage = false);

lib/screens/settings_screen.dart

@@ -1206,24 +1206,26 @@ class _SettingsScreenState extends State<SettingsScreen> {
       builder: (context) => AlertDialog(
         title: const Text('Max image size'),
         content: SingleChildScrollView(
-          child: Column(
-            mainAxisSize: MainAxisSize.min,
-            children: ImagePreferences.supportedSizes
-                .map(
-                  (size) => RadioListTile<int>(
-                    value: size,
-                    groupValue: _imageMaxSize,
-                    title: Text('${size}×$size px'),
-                    subtitle: size == ImagePreferences.defaultMaxSize
-                        ? const Text('Default')
-                        : null,
-                    onChanged: (value) {
-                      if (value != null) _saveImageMaxSize(value);
-                      Navigator.pop(context);
-                    },
-                  ),
-                )
-                .toList(),
+          child: RadioGroup<int>(
+            groupValue: _imageMaxSize,
+            onChanged: (value) {
+              if (value != null) _saveImageMaxSize(value);
+              Navigator.pop(context);
+            },
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: ImagePreferences.supportedSizes
+                  .map(
+                    (size) => RadioListTile<int>(
+                      value: size,
+                      title: Text('$size×$size px'),
+                      subtitle: size == ImagePreferences.defaultMaxSize
+                          ? const Text('Default')
+                          : null,
+                    ),
+                  )
+                  .toList(),
+            ),
           ),
         ),
         actions: [