5a23783e07
- Add missing modal CSS (.modal-overlay/.modal-dialog/.modal-header): the "Connect to Microsoft" auth modal was rendering unstyled inline at the bottom of the page. Now a centered dialog with backdrop. - Surface OAuth connect errors in the modal instead of silently reopening it with no explanation. - MainLayout: implement IDisposable so event handlers are actually unsubscribed (Dispose existed but was never invoked). - Wire up the Settings theme selector (was a dead control): drop the unsupported Dark option, call sptb.setTheme on save and on load, resolve System via prefers-color-scheme. - Add branded 404 page via UseStatusCodePagesWithReExecute + Routes <NotFound> (blank white page before). - Add .progress-fill.indeterminate animation and .progress-panel. - Home: replace inline JS hover handlers with a .feature-card CSS class. - Define missing --surface-2 variable referenced by MainLayout. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>