Each widget now has an independent enable/disable checkbox that gates its
visibility in the sidebar (new global_settings.widgets columns + GET /api/widgets),
and is collapsed by default behind a WidgetSection wrapper so the tab stays
manageable as more widgets get added. The four existing tab components
(WeatherTab/StocksTab/BookmarksTab/Poe2Tab) are reused unmodified as each
section's expanded content.
Claude
e6ac6cd061