Add general calendar events (recording, social, task, general); nav links; v1.1.16

- Four event types on the calendar: General, Recording, Social, Task — each color-coded
- + Event button opens form with type picker, title, date, notes, reminder
- Task events have a Mark Complete toggle; completed events show strikethrough
- Edit/delete popover for each event
- Email reminders work for calendar events same as episodes
- Added Email/Calendar nav links to /contacts header
- Added Email link to /calendar header (already had Admin)
- /email already links to Contacts and Calendar

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/state.js

@@ -93,6 +93,9 @@ export const state = {
   emailSettings: { signature: 'Grace and peace,\nVerse by Verse with Nate' },
   emailSettingsWritePromise: Promise.resolve(),
 
+  calendarEvents: [],
+  calendarEventsWritePromise: Promise.resolve(),
+
   lastBackupStatus: { ok: true, at: null, error: null, file: null },
   lastCachePurgeStatus: { ok: true, at: null, error: null },
   lastDeployHookStatus: { ok: true, at: null, error: null },