Tasks TUI:
- Add context support to TaskBackend interface (get_context, set_context,
get_contexts methods)
- Implement context methods in DstaskClient
- Add Context section to FilterSidebar (above projects/tags)
- Context changes persist via backend CLI
Calendar TUI:
- Remove duplicate header from InvitesPanel (use border_title instead)
- Fix border_title color to use $primary
- Fix WeekGrid to always scroll to work day start (7am) on mount
- Mail: Fix folder/account selector not triggering reload (use direct
fetch instead of reactive reload_needed flag)
- Tasks: Store all_projects/all_tags on mount so filters don't change
when filtering; add OR search for multiple tags
- Sync: Use rounded borders and border_title for sidebar/activity log
- Calendar: Remove padding from mini-calendar, add rounded border and
border_title to invites panel
- Create InvitesPanel widget showing pending invites from Microsoft Graph
- Add fetch_pending_invites() and respond_to_invite() API functions
- Invites load asynchronously in background on app mount
- Display invite subject, date/time, and organizer
- Add 'i' keybinding to focus invites panel
- Style: tentative invites shown in warning color
