fix: Phase 2 QA — all 25 remaining HIGH/MEDIUM/LOW issues

HIGH fixes (7):
- H1: VNCdirectory admin i18n — 30+ translation keys added
- H2: handleSave try/catch with error toast
- H3: Free/busy accountId scoping
- H4: cancelEventBookings filter by eventId
- H5: Resource picker static apiFetch import
- H6: Sharing-store toast messages via lastMessage state
- H7: roleLabel for all resource types

MEDIUM fixes (11):
- M1: identitySignatureMap cleanup on delete
- M2: Now-line relative positioning
- M3: Radial menu disabled item keyboard nav
- M4: Radial menu stable event listener via refs
- M5: cancelBooking error on missing booking
- M6: PasswordRow isMasked state flag
- M7: Extract shared rights into lib/sharing-rights.ts
- M8: VNCtalk client server-side guard
- M9: Collabora configManager instead of process.env
- M10: CONFIG_ENV_MAP VNCdirectory fields
- M11: SENSITIVE_CONFIG_KEYS field name unification

LOW fixes (7):
- L1-L3: Unused imports removed
- L4: aria-labels on close, clear, search, spinner
- L5-L7: Comments for intentional patterns, null guard

lib/calendar-freebusy.ts

@@ -52,6 +52,11 @@ function getEventRange(event: CalendarEvent): EventRange {
   };
 }
 
+// NOTE: this duplicates the ISO 8601 duration parsing in
+// components/calendar/event-card.tsx:parseDuration (which returns minutes
+// and only handles W/D/H/M via regex). This version returns milliseconds
+// and additionally handles seconds and sign. They serve different call
+// sites with different return types, so keep both for now.
 function parseDurationMs(duration: string): number {
   let ms = 0;
   let sign = 1;
@@ -120,7 +125,8 @@ export async function fetchFreeBusy(
   client: IJMAPClient,
   participants: { email: string }[],
   start: Date,
-  end: Date
+  end: Date,
+  accountId?: string
 ): Promise<Map<string, FreeBusySlot[]>> {
   const result = new Map<string, FreeBusySlot[]>();
 
@@ -139,7 +145,9 @@ export async function fetchFreeBusy(
   try {
     const events = await client.queryAllCalendarEvents(
       { after: start.toISOString(), before: end.toISOString() },
-      [{ property: "start", isAscending: true }]
+      [{ property: "start", isAscending: true }],
+      undefined,
+      accountId
     );
 
     for (const event of events) {