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/calendar/calendar-agenda-view.tsx

@@ -3,7 +3,7 @@
 import { useMemo, useRef, useEffect, useCallback } from "react";
 import { useTranslations, useFormatter } from "next-intl";
 import { format, parseISO, isToday, isTomorrow, startOfDay } from "date-fns";
-import { Calendar as CalendarIcon, MapPin, Users } from "lucide-react";
+import { MapPin, Users } from "lucide-react";
 import { cn } from "@/lib/utils";
 import { parseDuration, getEventColor } from "./event-card";
 import { getEventDayBounds, getPrimaryCalendarId } from "@/lib/calendar-utils";

components/calendar/calendar-sidebar-panel.tsx

@@ -2,7 +2,7 @@
 
 import { useState, useRef, useEffect, useMemo } from "react";
 import { useTranslations } from "next-intl";
-import { Globe, ListTodo, Plus, RefreshCw, Share2, Trash2 } from "lucide-react";
+import { Globe, ListTodo, RefreshCw, Share2, Trash2 } from "lucide-react";
 import { cn, formatDateTime } from "@/lib/utils";
 import type { Calendar } from "@/lib/jmap/types";
 import { CalendarColorPicker } from "@/components/settings/calendar-management-settings";

components/calendar/task-list-view.tsx

@@ -3,7 +3,7 @@
 import { useMemo, useCallback, useState } from "react";
 import { useTranslations } from "next-intl";
 import { format, parseISO, isPast, isToday, isTomorrow } from "date-fns";
-import { Check, Circle, Flag, CalendarDays, ListTodo, Plus } from "lucide-react";
+import { Check, Flag, CalendarDays, ListTodo, Plus } from "lucide-react";
 import { cn } from "@/lib/utils";
 import type { CalendarTask, Calendar } from "@/lib/jmap/types";
 import type { TaskViewFilter } from "@/stores/task-store";

components/calendar/task-modal.tsx

@@ -6,7 +6,7 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { X, Trash2, CalendarDays, Bell, Flag } from "lucide-react";
 import { format, parseISO } from "date-fns";
-import { cn } from "@/lib/utils";
+
 import type { CalendarTask, Calendar, CalendarEventAlert } from "@/lib/jmap/types";
 
 interface TaskModalProps {
@@ -43,7 +43,7 @@ export function TaskModal({
   onSave,
   onDelete,
   onClose,
-  isMobile,
+  isMobile: _isMobile,
 }: TaskModalProps) {
   const t = useTranslations("calendar");
   const isEdit = !!task;