Add unified task menu, Live Activity, and calendar event actions

Task context menu (new shared TaskMenuItems) consistent across Today,
Matrix, and Calendar: Pin · Date · Move · Priority · Tags · Add to Live
Activity · Delete. Adds TaskViewModel.setPriority.

Live Activity (ActivityKit):
- TaskActivityAttributes shared between app and widget targets
- LiveActivityManager (start/update/end/toggle, iOS 16.1+)
- TaskLiveActivity widget: lock-screen banner + Dynamic Island
- NSSupportsLiveActivities via project.yml; project regenerated

Calendar events (non-subscription, writable only):
- Edit via system EKEventEditViewController (EventEditView wrapper)
- Delete via new CalendarStore.deleteEvent

Also sweeps in prior in-progress edits already present in the working
tree (AuthManager, NotificationManager, TaskItem, task views) and the
updated ISSUES.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

project.yml

@@ -51,6 +51,7 @@ targets:
         INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone: "UIInterfaceOrientationPortrait UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight"
         ASSETCATALOG_COMPILER_APPICON_NAME: AppIcon
         ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME: AccentColor
+        INFOPLIST_KEY_NSSupportsLiveActivities: YES
         CODE_SIGN_STYLE: Automatic
         CODE_SIGN_ENTITLEMENTS: KisaniCal/KisaniCal.entitlements
         ENABLE_PREVIEWS: YES
@@ -66,6 +67,7 @@ targets:
     sources:
       - path: KisaniCalWidgets
       - path: KisaniCal/Managers/AppGroup.swift
+      - path: KisaniCal/Managers/TaskActivityAttributes.swift
     info:
       path: KisaniCalWidgets/Info.plist
       properties: