feat: P2.2 Create Appointment from Email + P2.4 Calendar Dashlet + P2.12 Action Wheel + P2.14 Share Files

- P2.2: 'Create Appointment' button in email viewer → pre-fills event modal
  with subject, body, participants, date. calendar-store newEventPrefill state.
- P2.4: MiniCalendarDashlet in sidebar bottom — month grid with event dots,
  day click navigates to calendar. Collapsible, respect firstDayOfWeek.
- P2.12: Custom radial menu (components/ui/radial-menu.tsx) — circular SVG
  menu with keyboard nav, animations. Wired into email-list, contact-list,
  file-browser, calendar-month-view right-click handlers.
- P2.14: 'Send as Attachment' button in file browser — opens compose tab
  with selected files pre-attached via Pro tab store.

stores/calendar-store.ts

@@ -251,6 +251,9 @@ interface CalendarStore {
   refreshICalSubscription: (client: IJMAPClient, subscriptionId: string) => Promise<void>;
   refreshAllSubscriptions: (client: IJMAPClient) => Promise<void>;
   isSubscriptionCalendar: (calendarId: string) => boolean;
+
+  newEventPrefill: { title?: string; description?: string; participants?: { name?: string; email: string }[]; date?: string } | null;
+  setNewEventPrefill: (prefill: { title?: string; description?: string; participants?: { name?: string; email: string }[]; date?: string } | null) => void;
 }
 
 const initialState = {
@@ -265,6 +268,7 @@ const initialState = {
   error: null as string | null,
   dateRange: null as { start: string; end: string } | null,
   icalSubscriptions: [] as ICalSubscription[],
+  newEventPrefill: null as { title?: string; description?: string; participants?: { name?: string; email: string }[]; date?: string } | null,
 };
 
 function getSafeCalendarViewMode(value: unknown): CalendarViewMode {
@@ -1009,6 +1013,8 @@ export const useCalendarStore = create<CalendarStore>()(
         return get().icalSubscriptions.some(s => s.calendarId === calendarId);
       },
 
+      setNewEventPrefill: (prefill) => set({ newEventPrefill: prefill }),
+
       addICalSubscription: async (client, url, name, color, refreshInterval = 60) => {
         // Normalize webcal(s):// → https:// so the server-side fetcher
         // (which only accepts http/https) doesn't reject every refresh.