fix: recurring events edit all instances issues

- Fix master event detection in getEvent() to find VEVENT without recurrence-id
- Add removeOverrides parameter to updateSeries() to control override deletion
- Fetch master event when editing 'all events' to preserve original start date
- Combine master's date with form's time when updating all instances
- Detect time changes separately from date changes to preserve optimistic updates
- Only remove overrides when date/time/timezone/repeat rules change
- Keep overrides when only properties (title, description, etc) change

Fixes:
1. Old UI not cleared when editing all events
2. Start date not preserved when editing from different instance
3. Solo overrides incorrectly removed when only properties changed
4. Optimistic updates lost when editing recurring events

src/features/Events/EventApi.ts

@@ -15,8 +15,27 @@ export async function getEvent(event: CalendarEvent, isMaster?: boolean) {
 
   const eventical = ICAL.parse(eventData);
 
+  let targetVevent;
+  if (isMaster) {
+    // Find master VEVENT (the one without recurrence-id)
+    const vevents = eventical[2].filter(
+      ([name]: string[]) => name === "vevent"
+    );
+    targetVevent = vevents.find(
+      ([, props]: [string, any[]]) =>
+        !props.find(([k]: string[]) => k.toLowerCase() === "recurrence-id")
+    );
+    if (!targetVevent) {
+      // Fallback to first VEVENT if no master found
+      targetVevent = eventical[2][1];
+    }
+  } else {
+    // For non-master, use first VEVENT as before
+    targetVevent = eventical[2][1];
+  }
+
   const eventjson = parseCalendarEvent(
-    eventical[2][1][1],
+    targetVevent[1],
     event.color ?? "",
     event.calId,
     event.URL
@@ -109,7 +128,8 @@ export const deleteEventInstance = async (
 
 export const updateSeries = async (
   event: CalendarEvent,
-  calOwnerEmail?: string
+  calOwnerEmail?: string,
+  removeOverrides: boolean = true
 ) => {
   const vevents = await getAllRecurrentEvent(event);
   const masterIndex = vevents.findIndex(
@@ -119,7 +139,7 @@ export const updateSeries = async (
   if (masterIndex === -1) {
     throw new Error("No master VEVENT found for this series");
   }
-  const rrule = vevents[0][1].find(([k]: string[]) => k === "rrule");
+  const rrule = vevents[masterIndex][1].find(([k]: string[]) => k === "rrule");
 
   const tzid = event.timezone;
 
@@ -128,12 +148,25 @@ export const updateSeries = async (
   if (!newRrule) {
     updatedMaster[1].push(rrule);
   }
-  vevents[masterIndex] = updatedMaster;
 
   const timezoneData = TIMEZONES.zones[event.timezone];
   const vtimezone = makeTimezone(timezoneData, event);
 
-  const newJCal = ["vcalendar", [], [...vevents, vtimezone.component.jCal]];
+  let finalVevents;
+  if (removeOverrides) {
+    // When date/time/timezone/repeat rules changed, remove all override instances
+    finalVevents = [updatedMaster];
+  } else {
+    // When only properties changed, keep override instances
+    vevents[masterIndex] = updatedMaster;
+    finalVevents = vevents;
+  }
+
+  const newJCal = [
+    "vcalendar",
+    [],
+    [...finalVevents, vtimezone.component.jCal],
+  ];
   return api(`dav${event.URL}`, {
     method: "PUT",
     body: JSON.stringify(newJCal),