feat(03-12): GREEN — WR-03 blank edit, WR-03 recurrence, WR-05 zone-consistent, IN-03

WR-03 blank: add occurrence?.uid to reset effect deps so form re-populates
when occurrence resolves in TanStack cache after form opens.

WR-03 recurrence: derive initial recurrence from occurrence?.recurrence
instead of hard-coding 'none'; defaults to 'none' when absent (v1 comment).

WR-05: rewrite parseDateTime to use getFullYear/getMonth/getDate/getHours/
getMinutes (all local accessors) — never mix toISOString() UTC date with
getHours() local time.

IN-03: export todayIso from calendarStore (was private); import into EventForm
and collapse getDefaultStartDate/getDefaultEndDate to todayIso() calls.

apps/pwa/src/components/EventForm.tsx

@@ -30,7 +30,7 @@
 import { useEffect, useRef, useState } from 'react'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { X, Loader2 } from 'lucide-react'
-import { useCalendarStore } from '../store/calendarStore.js'
+import { useCalendarStore, todayIso } from '../store/calendarStore.js'
 import {
   createEvent,
   updateEvent,
@@ -44,13 +44,8 @@ import type { CalendarOccurrence } from '../api/client.js'
 
 const LAST_CALENDAR_KEY = 'eventForm.lastCalendarUrl'
 
-function getDefaultStartDate(): string {
-  return new Date().toISOString().slice(0, 10)
-}
-
-function getDefaultEndDate(): string {
-  return new Date().toISOString().slice(0, 10)
-}
+// IN-03: todayIso is now imported from calendarStore (single source of truth).
+// getDefaultStartDate/getDefaultEndDate collapsed to todayIso() calls at use sites.
 
 // ── Helpers ────────────────────────────────────────────────────────────────────
 
@@ -80,23 +75,32 @@ function writeLastCalendarUrl(url: string): void {
 /**
  * Parse an ISO date string (possibly with time + offset) into
  * { date: 'YYYY-MM-DD', time: 'HH:MM' }. Falls back to today/09:00 if malformed.
+ *
+ * WR-05 fix: date and time are derived from the SAME local-accessor family.
+ * NEVER mix toISOString().slice(0,10) (UTC date) with getHours() (local time).
+ * Both date and time use getFullYear/getMonth/getDate/getHours/getMinutes so
+ * the pair describes the same wall-clock consistently in the viewer's zone.
  */
 function parseDateTime(iso: string): { date: string; time: string } {
   try {
     // Strip IANA bracket suffix e.g. '[America/Toronto]'
     const clean = iso.replace(/\[[^\]]*\]$/, '')
     if (/^\d{4}-\d{2}-\d{2}$/.test(iso)) {
-      // All-day date string
+      // All-day date string — use as-is (no time component)
       return { date: iso, time: '09:00' }
     }
     const d = new Date(clean)
     if (isNaN(d.getTime())) throw new Error('Invalid date')
-    const date = d.toISOString().slice(0, 10)
+    // WR-05: use ONLY local accessors so date and time are in the same zone frame.
+    // Do NOT use toISOString() here — it returns UTC, which can differ from local time.
+    const year = String(d.getFullYear())
+    const month = String(d.getMonth() + 1).padStart(2, '0')
+    const day = String(d.getDate()).padStart(2, '0')
     const hours = String(d.getHours()).padStart(2, '0')
     const mins = String(d.getMinutes()).padStart(2, '0')
-    return { date, time: `${hours}:${mins}` }
+    return { date: `${year}-${month}-${day}`, time: `${hours}:${mins}` }
   } catch {
-    return { date: getDefaultStartDate(), time: '09:00' }
+    return { date: todayIso(), time: '09:00' }
   }
 }
 
@@ -134,8 +138,8 @@ export function EventForm() {
 
   // ── Form state ──────────────────────────────────────────────────────────────
 
-  const initStart = occurrence ? parseDateTime(occurrence.start) : { date: getDefaultStartDate(), time: '09:00' }
-  const initEnd = occurrence ? parseDateTime(occurrence.end) : { date: getDefaultEndDate(), time: '10:00' }
+  const initStart = occurrence ? parseDateTime(occurrence.start) : { date: todayIso(), time: '09:00' }
+  const initEnd = occurrence ? parseDateTime(occurrence.end) : { date: todayIso(), time: '10:00' }
 
   const [title, setTitle] = useState(occurrence?.title ?? '')
   const [allDay, setAllDay] = useState(occurrence?.allDay ?? false)
@@ -163,22 +167,34 @@ export function EventForm() {
     }
   }, [writableCalendars]) // eslint-disable-line react-hooks/exhaustive-deps
 
-  // Reset form when opening (mode may change)
+  // Reset form when opening (mode may change) or when occurrence resolves in cache.
+  // WR-03: `occurrence` (via occurrence?.uid) is in the dep array so the effect
+  // re-runs when the occurrence arrives in the TanStack cache after form open.
+  // This prevents the "blank edit form" bug when the form opens before the cache
+  // has hydrated the occurrence for the requested UID.
   useEffect(() => {
     if (eventFormOpen) {
-      const startParsed = occurrence ? parseDateTime(occurrence.start) : { date: getDefaultStartDate(), time: '09:00' }
-      const endParsed = occurrence ? parseDateTime(occurrence.end) : { date: getDefaultEndDate(), time: '10:00' }
+      const startParsed = occurrence ? parseDateTime(occurrence.start) : { date: todayIso(), time: '09:00' }
+      const endParsed = occurrence ? parseDateTime(occurrence.end) : { date: todayIso(), time: '10:00' }
       setTitle(occurrence?.title ?? '')
       setAllDay(occurrence?.allDay ?? false)
       setStartDate(startParsed.date)
       setStartTime(startParsed.time)
       setEndDate(endParsed.date)
       setEndTime(endParsed.time)
-      setRecurrence('none')
+      // WR-03 recurrence: derive from occurrence if present; default 'none' only when
+      // genuinely absent. Note: occurrence.recurrence is not in CalendarOccurrence type
+      // (the API expand contract does not expose it in v1 — D-03). We cast to any to
+      // read it if a future API version adds it, and default to 'none' when not present
+      // (WR-03 v1 comment: occurrence edits whose recurrence is not in the cache default
+      // to 'none'; this will be addressed when the occurrence/expand contract is extended).
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const derivedRecurrence = (occurrence as any)?.recurrence as RecurrencePreset | undefined
+      setRecurrence(derivedRecurrence ?? 'none')
       setLocation(occurrence?.location ?? '')
       setDescription(occurrence?.description ?? '')
     }
-  }, [eventFormOpen, eventFormMode, eventFormUid]) // eslint-disable-line react-hooks/exhaustive-deps
+  }, [eventFormOpen, eventFormMode, eventFormUid, occurrence?.uid]) // eslint-disable-line react-hooks/exhaustive-deps
 
   // ── Validation state ────────────────────────────────────────────────────────