style(13-03): apply Prettier formatting across repo

Mechanical reformat — no logic changes. 398 files changed, 19125
insertions(+), 16457 deletions(-). Prettier 3.8.4 with .prettierrc
(singleQuote:true, semi:true, tabWidth:2, trailingComma:all,
printWidth:100). Isolated per D-13-08 for reviewability.

.planning/milestones/v1.0-phases/03-event-write-back-pwa-install/03-02-SUMMARY.md

@@ -22,8 +22,8 @@ tech-stack:
   added: []
   patterns:
     - "ICAL.Recur.fromString + new ICAL.Property('rrule') for RRULE serialization (addPropertyWithValue on string produces char-split output)"
-    - "ICAL.Time({ isDate: true }, ICAL.Timezone.localTimezone) for all-day DATE values (TS types require 2-arg constructor)"
-    - "ICAL.Time.fromJSDate(date, true) for timed UTC events (useUTC=true → Z suffix, no TZID)"
+    - 'ICAL.Time({ isDate: true }, ICAL.Timezone.localTimezone) for all-day DATE values (TS types require 2-arg constructor)'
+    - 'ICAL.Time.fromJSDate(date, true) for timed UTC events (useUTC=true → Z suffix, no TZID)'
     - "null etag passed as '' in tsdav calendarObject (safe default; tsdav skips If-Match header)"
 
 key-files:
@@ -34,7 +34,7 @@ key-files:
 
 key-decisions:
   - "D-02-RRULE: ICAL.Recur.fromString + ICAL.Property('rrule') is required for correct RRULE serialization. ICAL.Component.addPropertyWithValue('rrule', string) treats the string as a TEXT value and serializes each character individually — unusable. Use ICAL.Recur.fromString → prop.setValue(recur) → vevent.addProperty(prop)."
-  - "D-02-DATE-ZONE: ICAL.Time constructor TypeScript signature requires 2 args (data, zone). For all-day DATE values, isDate:true suppresses any TZID output regardless of which zone is passed. ICAL.Timezone.localTimezone is the safe choice; it satisfies the type without adding TZID to DATE properties."
+  - 'D-02-DATE-ZONE: ICAL.Time constructor TypeScript signature requires 2 args (data, zone). For all-day DATE values, isDate:true suppresses any TZID output regardless of which zone is passed. ICAL.Timezone.localTimezone is the safe choice; it satisfies the type without adding TZID to DATE properties.'
 
 # Metrics
 duration: ~4min
@@ -83,6 +83,7 @@ completed: 2026-06-05
 ### Auto-fixed Issues
 
 **1. [Rule 1 - Bug] RRULE serialization via addPropertyWithValue produces character-split output**
+
 - **Found during:** Task 1 — first test run showed `RRULE:0=F;1=R;2=E;3=Q...` instead of `RRULE:FREQ=WEEKLY;BYDAY=MO`
 - **Issue:** `vevent.addPropertyWithValue('rrule', string)` passes a JavaScript string where ical.js expects a RECUR value type. ical.js iterates the string object properties (0, 1, 2...) and serializes each character as a key-value pair.
 - **Fix:** Use `ICAL.Recur.fromString(params.rruleString)` to parse the string into a RECUR value object, then `new ICAL.Property('rrule')` + `prop.setValue(recur)` + `vevent.addProperty(prop)`.
@@ -90,6 +91,7 @@ completed: 2026-06-05
 - **Commit:** `a1243c1` (combined with Task 2)
 
 **2. [Rule 1 - Bug] ICAL.Time constructor TypeScript type error (2 args required)**
+
 - **Found during:** Task 2 — `tsc --noEmit` reported `Expected 2 arguments, but got 1` for `new ICAL.Time({ isDate: true })` calls
 - **Issue:** ical.js TypeScript declarations define `constructor(data: timeInit, zone: Timezone)` as requiring both arguments, though the JavaScript implementation accepts 1.
 - **Fix:** Pass `ICAL.Timezone.localTimezone` as the second arg. For `isDate: true` DATE values, the zone has no effect on serialization — it does not add TZID to the property.
@@ -115,5 +117,6 @@ No new network endpoints or auth paths introduced. `broker/write.ts` is a low-le
 - `pnpm --filter @familysync/api exec tsc --noEmit` — clean (no errors)
 
 ---
-*Phase: 03-event-write-back-pwa-install*
-*Completed: 2026-06-05*
+
+_Phase: 03-event-write-back-pwa-install_
+_Completed: 2026-06-05_