fix: resolve IPC serialization, auth change wiring, and error→followup transition (qa-requested)

Fixes:
- Build PRReviewStatePayload object in emitStateToRenderer instead of sending raw args
- Wire up handleAuthChange via ipcMain listener for GITHUB_AUTH_CHANGED
- Add START_FOLLOWUP_REVIEW transition to error state in pr-review-machine
- Update state manager tests to verify PRReviewStatePayload shape

Verified:
- All 3279 tests pass
- TypeScript compilation clean

QA Fix Session: 1

Co-Authored-By: Claude Opus 4.6 <[email protected]>

apps/frontend/src/main/__tests__/pr-review-state-manager.test.ts

@@ -160,20 +160,35 @@ describe('PRReviewStateManager', () => {
         expect.any(Function),
         'github:pr:reviewStateChange',
         expect.any(String),
-        expect.any(String),
-        expect.anything()
+        expect.objectContaining({ state: expect.any(String) })
       );
     });
 
-    it('should include state value and context in payload', () => {
+    it('should emit PRReviewStatePayload with correct shape', () => {
       manager.handleStartReview(projectId, prNumber);
       // Find the call that emits 'reviewing' state
       const reviewingCall = mockSafeSendToRenderer.mock.calls.find(
-        (call: unknown[]) => call[3] === 'reviewing'
+        (call: unknown[]) => {
+          const payload = call[3] as Record<string, unknown> | undefined;
+          return payload && typeof payload === 'object' && payload.state === 'reviewing';
+        }
       );
       expect(reviewingCall).toBeDefined();
       expect(reviewingCall![2]).toBe(`${projectId}:${prNumber}`);
-      expect(reviewingCall![4]).toEqual(expect.objectContaining({ prNumber, projectId }));
+      const payload = reviewingCall![3] as Record<string, unknown>;
+      expect(payload).toEqual(expect.objectContaining({
+        state: 'reviewing',
+        prNumber,
+        projectId,
+        isReviewing: true,
+        startedAt: expect.any(String),
+        progress: null,
+        result: null,
+        previousResult: null,
+        error: null,
+        isExternalReview: false,
+        isFollowup: false,
+      }));
     });
 
     it('should use projectId:prNumber as key format', () => {
@@ -244,8 +259,8 @@ describe('PRReviewStateManager', () => {
       // Should emit idle/null state for each PR
       expect(mockSafeSendToRenderer).toHaveBeenCalledTimes(2);
       for (const call of mockSafeSendToRenderer.mock.calls) {
-        expect(call[3]).toBe('idle'); // stateValue
-        expect(call[4]).toBeNull(); // context
+        const payload = call[3] as Record<string, unknown>;
+        expect(payload).toEqual(expect.objectContaining({ state: 'idle' }));
       }
     });
 

apps/frontend/src/main/ipc-handlers/github/oauth-handlers.ts

@@ -51,6 +51,8 @@ function sendAuthChangedToRenderer(oldUsername: string | null, newUsername: stri
   for (const win of windows) {
     win.webContents.send(IPC_CHANNELS.GITHUB_AUTH_CHANGED, payload);
   }
+  // Emit on ipcMain so main-process listeners (e.g., PRReviewStateManager) can react
+  ipcMain.emit(IPC_CHANNELS.GITHUB_AUTH_CHANGED, payload);
 }
 
 /**

apps/frontend/src/main/ipc-handlers/github/pr-handlers.ts

@@ -1670,6 +1670,11 @@ export function registerPRHandlers(getMainWindow: () => BrowserWindow | null): v
   // Create the XState-based PR review state manager
   const prReviewStateManager = new PRReviewStateManager(getMainWindow);
 
+  // Clear all PR review actors when GitHub auth changes (account swap)
+  ipcMain.on(IPC_CHANNELS.GITHUB_AUTH_CHANGED, () => {
+    prReviewStateManager.handleAuthChange();
+  });
+
   // List open PRs - fetches up to 100 open PRs at once, returns hasNextPage and endCursor from API
   ipcMain.handle(
     IPC_CHANNELS.GITHUB_PR_LIST,

apps/frontend/src/main/pr-review-state-manager.ts

@@ -2,7 +2,7 @@ import { createActor } from 'xstate';
 import type { ActorRefFrom } from 'xstate';
 import type { BrowserWindow } from 'electron';
 import { prReviewMachine, type PRReviewEvent, type PRReviewContext } from '../shared/state-machines';
-import type { PRReviewProgress, PRReviewResult } from '../preload/api/modules/github-api';
+import type { PRReviewProgress, PRReviewResult, PRReviewStatePayload } from '../preload/api/modules/github-api';
 import { IPC_CHANNELS } from '../shared/constants';
 import { safeSendToRenderer } from './ipc-handlers/utils';
 
@@ -149,14 +149,27 @@ export class PRReviewStateManager {
     snapshot: ReturnType<PRReviewActor['getSnapshot']> | null
   ): void {
     const stateValue = snapshot ? String(snapshot.value) : 'idle';
-    const context = snapshot ? snapshot.context : null;
+    const ctx = snapshot?.context ?? null;
+
+    const payload: PRReviewStatePayload = {
+      state: stateValue,
+      prNumber: ctx?.prNumber ?? 0,
+      projectId: ctx?.projectId ?? '',
+      isReviewing: stateValue === 'reviewing' || stateValue === 'externalReview',
+      startedAt: ctx?.startedAt ?? null,
+      progress: ctx?.progress ?? null,
+      result: ctx?.result ?? null,
+      previousResult: ctx?.previousResult ?? null,
+      error: ctx?.error ?? null,
+      isExternalReview: ctx?.isExternalReview ?? false,
+      isFollowup: ctx?.isFollowup ?? false,
+    };
 
     safeSendToRenderer(
       this.getMainWindow,
       IPC_CHANNELS.GITHUB_PR_REVIEW_STATE_CHANGE,
       key,
-      stateValue,
-      context
+      payload
     );
   }
 }

apps/frontend/src/shared/state-machines/__tests__/pr-review-machine.test.ts

@@ -152,6 +152,20 @@ describe('prReviewMachine', () => {
       expect(snapshot.context.error).toBeNull();
       expect(snapshot.context.result).toEqual(mockResult);
     });
+
+    it('should allow starting a follow-up review from error state with previousResult preserved', () => {
+      const snapshot = runEvents([
+        { type: 'START_REVIEW', prNumber: 42, projectId: 'proj-1' },
+        { type: 'REVIEW_COMPLETE', result: mockResult },
+        { type: 'START_FOLLOWUP_REVIEW', prNumber: 42, projectId: 'proj-1', previousResult: mockResult },
+        { type: 'REVIEW_ERROR', error: 'Follow-up failed' },
+        { type: 'START_FOLLOWUP_REVIEW', prNumber: 42, projectId: 'proj-1', previousResult: mockResult },
+      ]);
+
+      expect(snapshot.value).toBe('reviewing');
+      expect(snapshot.context.previousResult).toEqual(mockResult);
+      expect(snapshot.context.isFollowup).toBe(true);
+    });
   });
 
   describe('clear review', () => {

apps/frontend/src/shared/state-machines/pr-review-machine.ts

@@ -118,6 +118,10 @@ export const prReviewMachine = createMachine(
             target: 'reviewing',
             actions: 'setReviewStart',
           },
+          START_FOLLOWUP_REVIEW: {
+            target: 'reviewing',
+            actions: 'setFollowupReviewStart',
+          },
           CLEAR_REVIEW: {
             target: 'idle',
             actions: 'clearContext',