0520f0dc5e
Add an in-app 7-day history chart and opt-in usage alerts, the two features requested from the macOS Claude-Usage-Tracker that map cleanly to an Android widget app. History: - UsageSnapshot model; PreferencesManager records session/weekly utilization on every refresh (7-day retention, <=600 points, collapses readings under 2 min apart to avoid worker+manual double-logging). - HistoryChartView: dependency-free Canvas line chart (session/weekly, 0/50/100% gridlines), breaks the line across >35-min gaps. - New HISTORY card with chart + legend. Notifications: - Notifier posts when session/weekly crosses a user threshold, at most once per limit window (keyed on reset-epoch, re-arms on rollover). - USAGE ALERTS card: enable switch + session/weekly sliders (50-100%, defaults 90/85). POST_NOTIFICATIONS permission + runtime request. - Wired into the existing 5-min background worker. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>