Add automatic calendar sync on editor initialization

Calendars now sync automatically when the editor starts, eliminating the
need for manual sync after opening SilverBullet.

Co-authored-by: Claude <noreply@anthropic.com>
Signed-off-by: Alexandre Nicolaie <xunleii@users.noreply.github.com>

icalendar.plug.yaml

@@ -7,6 +7,8 @@ functions:
     command:
       name: "iCalendar: Sync"
       priority: -1
+    events:
+      - editor:init
   forceSync:
     path: ./icalendar.ts:forceSync
     command: