- Flesh out ReportsTrendsPage with internal subview toggle
(global / byCategory) and ViewModeToggle (storage key reports-viewmode-trends)
- Reuse existing MonthlyTrendsChart/Table and CategoryOverTimeChart/Table
without modification; wire them through useTrends + useReportsPeriod so the
URL period is respected
- Add reports.trends.subviewGlobal / subviewByCategory keys in FR + EN
Fixes#72
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>