Phase 2 Task 33. Components can now ask "is this feature on?", "how many
sessions left?", and "what stage is the trial in?" without re-implementing
the read against useBillingStore.
- useFeature(flagKey): boolean — reads enabledFeatures from store
- useFeatureLimit(field): { used, limit, percentage, isAtLimit, isLoading }
with non-blocking 60s module-level cache and graceful 404 degradation
- useTrialBanner(): derives stage from subscription status + trial countdown,
returns null on initial load to prevent flicker
- usageApi.getCount(field) — calls /api/v1/usage/{field}; backend endpoint
is not yet implemented (planned), so the hook degrades to used=0
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
