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/smime/pkcs12-import.ts

@@ -1,7 +1,6 @@
 import * as asn1js from 'asn1js';
 import * as pkijs from 'pkijs';
 import {
-  parseCertificateDer,
   extractCertificateInfo,
   classifyCapabilities,
 } from './certificate-utils';
@@ -36,7 +35,6 @@ export async function importPkcs12(
 
   // Verify MAC if present
   if (pfx.macData) {
-    const macOk = await pfx.parsedValue?.integrityMode === undefined || true;
     // PKIjs handles MAC verification internally during parseInternalValues
   }