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/contacts/__tests__/contact-form.test.tsx

@@ -66,7 +66,7 @@ describe('ContactForm', () => {
     const onSave = vi.fn().mockResolvedValue(undefined);
     render(<ContactForm onSave={onSave} onCancel={vi.fn()} />);
 
-    const inputs = screen.getAllByRole('textbox');
+    const _inputs = screen.getAllByRole('textbox');
     const givenNameInput = screen.getByPlaceholderText('given_name');
     fireEvent.change(givenNameInput, { target: { value: 'Jane' } });