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/layout/icon-picker.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useState, useMemo, useRef, useEffect, useCallback } from 'react';
+import { useState, useMemo, useRef, useCallback } from 'react';
 import { useTranslations } from 'next-intl';
 import { icons as lucideIcons, type LucideIcon } from 'lucide-react';
 import { Search, X } from 'lucide-react';

components/layout/navigation-rail.tsx

@@ -2,7 +2,7 @@
 
 import { useState, useRef, useEffect, useCallback } from "react";
 import { createPortal } from "react-dom";
-import { Mail, Calendar, BookUser, HardDrive, Settings, LogOut, Keyboard, Plus } from "lucide-react";
+import { Mail, Calendar, BookUser, HardDrive, Settings, Keyboard, Plus } from "lucide-react";
 import { AccountSwitcher } from "./account-switcher";
 import { icons as lucideIcons, type LucideIcon } from "lucide-react";
 import { useConfig } from "@/hooks/use-config";

components/layout/sidebar-apps-modal.tsx

@@ -2,7 +2,7 @@
 
 import { useState, useCallback } from 'react';
 import { useTranslations } from 'next-intl';
-import { X, Plus, Pencil, Trash2, GripVertical, ExternalLink, PanelRight } from 'lucide-react';
+import { X, Plus, Pencil, Trash2, ExternalLink, PanelRight } from 'lucide-react';
 import { icons as lucideIcons, type LucideIcon } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { Button } from '@/components/ui/button';

components/layout/sidebar.tsx

@@ -429,7 +429,7 @@ export function Sidebar({
   className,
 }: SidebarProps) {
   const { sidebarCollapsed: isCollapsed, toggleSidebarCollapsed } = useUIStore();
-  const { primaryIdentity } = useAuthStore();
+  const { primaryIdentity: _primaryIdentity } = useAuthStore();
   const [expandedFolders, setExpandedFolders] = useState<Set<string>>(new Set());
   const [tagsExpanded, setTagsExpanded] = useState(() => {
     try {