fix: resolve all 69 ESLint warnings across 40 files

- Remove unused imports (Mail, CalendarIcon, Plus, Circle, cn, Link,
  MessageCircle, User, Tag, FolderUp, useEffect, LogOut, GripVertical,
  Check, X, HoverActionsMode, HoverActionsCorner, asn1js, Convert, etc.)
- Prefix unused variables/params with underscore to satisfy no-unused-vars
- Add missing React hook dependencies (exhaustive-deps)
- Wrap handleNavigateUp in useCallback and selectedGroupMembers in useMemo
- Remove unused eslint-disable directives in jmap/client.ts
- Replace as any with typed casts in filter-store and smime-store tests
- Remove dead code (macOk assignment, unused now variable)

lib/vcard.ts

@@ -1,4 +1,4 @@
-import type { ContactCard, NameComponent, ContactMedia, ContactOnlineService, AnniversaryDate, PartialDate } from "@/lib/jmap/types";
+import type { ContactCard, NameComponent, ContactOnlineService, AnniversaryDate, PartialDate } from "@/lib/jmap/types";
 
 // Convert RFC 9553 AnniversaryDate (PartialDate|Timestamp|string) to vCard date string
 function anniversaryDateToVcardString(date: AnniversaryDate): string {