fix(02): populate hasRrule on every sync upsert so recurring masters are flagged

- Use ICAL.Event.isRecurring() (parity with expand.ts) to detect RRULE/RDATE
- Add hasRrule to .values() INSERT and .onDuplicateKeyUpdate() SET so the flag
  is set on first sync and self-heals on every subsequent re-sync
- Without this fix every event had has_rrule=0 (column default), causing the
  events route recurring-master pre-filter to return zero recurring occurrences
- Add sync.test.ts cases: hasRrule=true for timed+all-day recurring VEVENTs,
  hasRrule=false for non-recurring, and hasRrule in onDuplicateKeyUpdate.set

apps/api/src/broker/sync.ts

@@ -89,6 +89,10 @@ export async function syncCalendar(
     // D-13 / Pitfall #3: isDate=true → DATE column; isDate=false → TIMESTAMP column
     const allDay: boolean = dtstart?.isDate ?? false
 
+    // Determine if this event is a recurring master (has RRULE or RDATE).
+    // Use ICAL.Event.isRecurring() for parity with expand.ts — it checks both properties.
+    const isRecurring: boolean = new ICAL.Event(vevent).isRecurring()
+
     // dtstartDate: Drizzle's `date` column accepts a Date object or null.
     // We convert the YYYY-MM-DD string from ical.js to a Date (at midnight UTC) so
     // Drizzle serialises it correctly as a DATE without a time component.
@@ -106,6 +110,7 @@ export async function syncCalendar(
         dtstartUtc: dtstartUtcValue,
         dtstartDate: dtstartDateValue,
         allDay,
+        hasRrule: isRecurring,
       })
       .onDuplicateKeyUpdate({
         set: {
@@ -114,6 +119,7 @@ export async function syncCalendar(
           dtstartUtc: dtstartUtcValue,
           dtstartDate: dtstartDateValue,
           allDay,
+          hasRrule: isRecurring,
           updatedAt: new Date(),
         },
       })