# Session Loop Bug (Returned)

## Issue Description
The session refresh loop bug has returned. After completing setup and the server restarts, the UI flashes/loops rapidly if you're on the dashboard, agents, or settings pages. User must manually logout and log back in to stop the loop.

**Previous fix:** Commit 7b77641 - "fix: resolve 401 session refresh loop"
- Added logout() call in Setup.tsx before configuration
- Cleared auth state on 401 in store
- Disabled retries in API client

## Current Behavior

**Steps to reproduce:**
1. Complete setup wizard
2. Click "Restart Server" button (or restart manually)
3. Server goes down, Docker components restart
4. UI automatically redirects from setup to dashboard
5. **BUG:** Screen starts flashing/rapid refresh loop
6. Clicking Logout stops the loop
7. Logging back in works fine

## Suspected Cause

The SetupCompletionChecker component is polling every 3 seconds and has a dependency array issue:

```typescript
useEffect(() => {
  const checkSetupStatus = async () => { ... }
  checkSetupStatus();
  const interval = setInterval(checkSetupStatus, 3000);
  return () => clearInterval(interval);
}, [wasInSetupMode, location.pathname, navigate]);  // ← Problem here
```

**Issue:** `wasInSetupMode` is in the dependency array. When it changes from `false` to `true` to `false`, it triggers new effect runs, creating multiple overlapping intervals without properly cleaning up the old ones.

During docker restart:
1. Initial render: creates interval 1
2. Server goes down: can't fetch health, sets wasInSetupMode
3. Effect re-runs: interval 1 still running, creates interval 2
4. Server comes back: detects not in setup mode
5. Effect re-runs again: interval 1 & 2 still running, creates interval 3
6. Now 3+ intervals all polling every 3 seconds = rapid flashing

## Potential Fix Options

### Option 1: Remove wasInSetupMode from dependencies
```typescript
useEffect(() => {
  let wasInSetup = false;

  const checkSetupStatus = async () => {
    // ... existing logic using wasInSetup local variable
  };

  checkSetupStatus();
  const interval = setInterval(checkSetupStatus, 3000);
  return () => clearInterval(interval);
}, [location.pathname, navigate]);  // Only pathname and navigate
```

### Option 2: Add interval guard
```typescript
const [intervalId, setIntervalId] = useState<number | null>(null);

useEffect(() => {
  // Clear any existing interval first
  if (intervalId) {
    clearInterval(intervalId);
  }

  const checkSetupStatus = async () => { ... };
  checkSetupStatus();
  const newInterval = setInterval(checkSetupStatus, 3000);
  setIntervalId(newInterval);

  return () => clearInterval(newInterval);
}, [wasInSetupMode, location.pathname, navigate]);
```

### Option 3: Increase polling interval during transitions
```typescript
const pollingInterval = wasInSetupMode ? 5000 : 3000; // Slower during transition
const interval = setInterval(checkSetupStatus, pollingInterval);
```

### Option 4: Stop polling after successful redirect
```typescript
if (wasInSetupMode && !currentSetupMode && location.pathname === '/setup') {
  console.log('Setup completed - redirecting to login');
  navigate('/login', { replace: true });
  // Don't set up interval again
  return;
}
```

## Testing

After applying fix:

```bash
# 1. Fresh setup
docker-compose down -v --remove-orphans
rm config/.env
docker-compose build --no-cache
cp config/.env.bootstrap.example config/.env
docker-compose up -d

# 2. Complete setup wizard
# 3. Restart server via UI or manually
docker-compose restart server

# 4. Watch browser console for:
#    - Multiple "checking setup status" logs
#    - 401 errors
#    - Rapid API calls to /health endpoint

# 5. Expected: No flashing, clean redirect to login
```

## Related Files

- `aggregator-web/src/components/SetupCompletionChecker.tsx` - Main component
- `aggregator-web/src/lib/store.ts` - Auth store with logout()
- `aggregator-web/src/pages/Setup.tsx` - Calls logout before configure
- `aggregator-web/src/lib/api.ts` - API retry logic

## Notes

This bug only manifests during the server restart after setup completion, making it hard to reproduce without a full cycle. The previous fix (commit 7b77641) addressed the 401 loop but didn't fully solve the interval cleanup issue.