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)

components/email/email-context-menu.tsx

@@ -132,7 +132,7 @@ export function EmailContextMenu({
   onEditDraft,
 }: EmailContextMenuProps) {
   const t = useTranslations("context_menu");
-  const tColor = useTranslations("email_viewer.color_tag");
+  const _tColor = useTranslations("email_viewer.color_tag");
   const emailKeywords = useSettingsStore((state) => state.emailKeywords);
   const isUnread = !email.keywords?.$seen;
   const isStarred = email.keywords?.$flagged;