0.2.5: Reactive Quota Indicators

• Added an immediate quota-display response to the specific native Anthropic subscription account-limit error. At most one window with strictly less than 5% remaining is inferred exhausted; when both are near-empty, an empirical weekly-to-five-hour budget ratio of 6:1 selects the smaller equivalent balance, preferring five-hour on ties. An already exhausted measured window leaves the other untouched. The shared signal makes no extra quota requests and preserves measured data, leadership and retry deadlines; a successful refresh started after the signal restores authoritative values. Other providers, proxies, API-key models, generic throttling and Fast credit errors do not trigger it.
• Changed shared quota polling from every three minutes to every two minutes, with follower takeover after two minutes and thirty seconds. Shared usage-endpoint failure backoff is preserved.