fix: Buffer feature-flag subscribers registered before init

[charlesvien]

Problem

useFeatureFlag callers that mount before App's init useEffect runs subscribe via onFeatureFlagsLoaded while PostHog is uninitialized, so the no-op return silently drops the subscription. When flags later resolve, nothing fires and the hook stays stuck on its initial value for the rest of the session.

Closes #2123

Changes

1. Buffer onFeatureFlagsLoaded callbacks added before PostHog initializes
2. Drain the buffer into posthog.onFeatureFlags at the end of initializePostHog
3. Return a cleanup that unsubscribes from both the buffer and PostHog

How did you test this?

Manually

Publish to changelog?

[charlesvien]

• fix: Buffer feature-flag subscribers registered before init #2267 : 2 dependent PRs (#2268 , #2270 ) 👈 (View in Graphite)
• feat: Add nightly cleanup of stale draft releases #2239
• main

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[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
apps/code/src/renderer/utils/analytics.ts:56-59
After the drain loop, every pre-init listener remains in `pendingFlagListeners` for the entire lifetime of the component — so the Set holds a reference in parallel with posthog's own internal listener list. Clearing the Set after draining frees that duplicate reference early; the cleanup closure still works correctly because `listener.unsubscribe?.()` handles the posthog unsubscription, and `pendingFlagListeners.delete(listener)` gracefully no-ops on a missing key.

```suggestion
  for (const listener of pendingFlagListeners) {
    listener.unsubscribe = posthog.onFeatureFlags(listener.callback);
  }
  pendingFlagListeners.clear();
}
```

_{Reviews (1): Last reviewed commit: "Buffer feature-flag subscribers register..." | Re-trigger Greptile}

[tatoalo]

let's goooo

[charlesvien]

Merge activity

• May 21, 7:54 AM UTC: @charlesvien merged this pull request with Graphite.