fix(app): treat in-progress conversation 404 as benign

app/e2e/SKILL.md

@@ -402,6 +402,17 @@ After making changes, verify them in the live app:
 4. Capture evidence: `agent-flutter screenshot /tmp/evidence.png`
 5. Generate video: `ffmpeg -framerate 1 -pattern_type glob -i '/tmp/e2e-*.png' -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1" -c:v libx264 -pix_fmt yuv420p /tmp/report.mp4`
 
+### Process-in-progress 404 race (#9241)
+
+When WebSocket auto-finalize races `POST /v1/conversations`, the server returns HTTP 404 (`Conversation in progress not found`). That is benign — the app must return `null` and must **not** surface a crash overlay or report to Crashlytics.
+
+1. With auth + backend connected, start a short phone-mic capture, then stop while the listen WebSocket is active.
+2. `agent-flutter snapshot -i --json` — confirm no crash/error dialog after the processing chip dismisses.
+3. Optional: `agent-flutter find type snackbar` should not match a fatal error after stop.
+4. Evidence: `agent-flutter screenshot /tmp/process-in-progress-404.png`
+
+Hermetic regression: `cd app && flutter test test/backend/process_in_progress_conversation_test.dart`.
+
 ## Decision Tree
 
 | Problem | Solution |

app/lib/backend/http/api/conversations.dart

@@ -21,17 +21,35 @@ Future<CreateConversationResponse?> processInProgressConversation() async {
     body: jsonEncode({}),
   );
   if (response == null) return null;
+  return interpretProcessInProgressConversationResponse(
+    response,
+    reportUnexpectedFailure: (body) {
+      // TODO: Server returns 304 doesn't recover
+      PlatformManager.instance.crashReporter.reportCrash(
+        Exception('Failed to create conversation'),
+        StackTrace.current,
+        userAttributes: {'response': body},
+      );
+    },
+  );
+}
+
+/// Maps POST /v1/conversations status codes. HTTP 404 is benign when WebSocket
+/// auto-finalize races this call and the in-progress pointer is already gone.
+@visibleForTesting
+CreateConversationResponse? interpretProcessInProgressConversationResponse(
+  http.Response response, {
+  required void Function(String body) reportUnexpectedFailure,
+}) {
   Logger.debug('createConversationServer: ${response.body}');
   if (response.statusCode == 200) {
     return CreateConversationResponse.fromGeneratedWireJson(jsonDecode(response.body) as Map<String, dynamic>);
-  } else {
-    // TODO: Server returns 304 doesn't recover
-    PlatformManager.instance.crashReporter.reportCrash(
-      Exception('Failed to create conversation'),
-      StackTrace.current,
-      userAttributes: {'response': response.body},
-    );
   }
+  if (response.statusCode == 404) {
+    Logger.debug('processInProgressConversation: in-progress conversation not found (likely already finalized)');
+    return null;
+  }
+  reportUnexpectedFailure(response.body);
   return null;
 }
 

app/test/backend/process_in_progress_conversation_test.dart

@@ -0,0 +1,56 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:omi/backend/http/api/conversations.dart';
+
+void main() {
+  group('interpretProcessInProgressConversationResponse', () {
+    test('HTTP 200 parses CreateConversationResponse', () {
+      const body = '''
+{
+  "messages": [],
+  "conversation": {
+    "id": "conv-123",
+    "created_at": "2025-01-15T10:30:00.000Z",
+    "started_at": "2025-01-15T10:30:00.000Z",
+    "finished_at": null,
+    "summary": "Overview",
+    "structured": {"title": "Test", "overview": "Overview"}
+  }
+}
+''';
+
+      final result = interpretProcessInProgressConversationResponse(
+        http.Response(body, 200),
+        reportUnexpectedFailure: (_) => fail('unexpected failure callback'),
+      );
+
+      expect(result, isNotNull);
+      expect(result!.conversation?.id, 'conv-123');
+      expect(result.messages, isEmpty);
+    });
+
+    test('HTTP 404 returns null without reporting crash', () {
+      var reported = false;
+
+      final result = interpretProcessInProgressConversationResponse(
+        http.Response('{"detail":"Conversation in progress not found"}', 404),
+        reportUnexpectedFailure: (_) => reported = true,
+      );
+
+      expect(result, isNull);
+      expect(reported, isFalse);
+    });
+
+    test('HTTP 500 reports unexpected failure and returns null', () {
+      var reportedBody = '';
+
+      final result = interpretProcessInProgressConversationResponse(
+        http.Response('{"detail":"Internal Server Error"}', 500),
+        reportUnexpectedFailure: (body) => reportedBody = body,
+      );
+
+      expect(result, isNull);
+      expect(reportedBody, '{"detail":"Internal Server Error"}');
+    });
+  });
+}