Tweak send no-response handling

frontend/src/components/MessageInput.tsx

@@ -24,6 +24,7 @@ const CHANNEL_WARNING_THRESHOLD = 120; // Conservative for multi-hop
 const CHANNEL_DANGER_BUFFER = 8; // Red zone starts this many bytes before hard limit
 
 const textEncoder = new TextEncoder();
+const RADIO_NO_RESPONSE_SNIPPET = 'no response was heard back';
 /** Get UTF-8 byte length of a string (LoRa packets are byte-constrained, not character-constrained). */
 function byteLen(s: string): number {
   return textEncoder.encode(s).length;
@@ -118,8 +119,11 @@ export const MessageInput = forwardRef<MessageInputHandle, MessageInputProps>(fu
         setText('');
       } catch (err) {
         console.error('Failed to send message:', err);
-        toast.error('Failed to send message', {
-          description: err instanceof Error ? err.message : 'Check radio connection',
+        const description = err instanceof Error ? err.message : 'Check radio connection';
+        const isRadioNoResponse =
+          err instanceof Error && err.message.toLowerCase().includes(RADIO_NO_RESPONSE_SNIPPET);
+        toast.error(isRadioNoResponse ? 'Radio did not confirm send' : 'Failed to send message', {
+          description,
         });
         return;
       } finally {

frontend/src/test/messageInput.test.tsx

@@ -9,12 +9,18 @@ import { render, screen, fireEvent } from '@testing-library/react';
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 
 import { MessageInput } from '../components/MessageInput';
+import { toast } from '../components/ui/sonner';
 
 // Mock sonner (toast)
 vi.mock('../components/ui/sonner', () => ({
   toast: { success: vi.fn(), error: vi.fn() },
 }));
 
+const mockToast = toast as unknown as {
+  success: ReturnType<typeof vi.fn>;
+  error: ReturnType<typeof vi.fn>;
+};
+
 const textEncoder = new TextEncoder();
 
 function byteLen(s: string): number {
@@ -182,4 +188,24 @@ describe('MessageInput', () => {
       expect(getSendButton()).toBeEnabled();
     });
   });
+
+  describe('send failure toasts', () => {
+    it('shows the radio no-response toast when the send outcome is unknown', async () => {
+      onSend.mockRejectedValueOnce(
+        new Error(
+          'Send command was issued to the radio, but no response was heard back. The message may or may not have sent successfully.'
+        )
+      );
+      renderInput({ conversationType: 'contact' });
+
+      fireEvent.change(getInput(), { target: { value: 'Hello' } });
+      fireEvent.click(getSendButton());
+
+      expect(await screen.findByDisplayValue('Hello')).toBeTruthy();
+      expect(mockToast.error).toHaveBeenCalledWith('Radio did not confirm send', {
+        description:
+          'Send command was issued to the radio, but no response was heard back. The message may or may not have sent successfully.',
+      });
+    });
+  });
 });