feat(frontend): draft/publish, certificate approval UI, contributors, leaderboard tiers

- admin-studio: chapter/lesson publish toggle with Draft/Published badges; per-chapter accordion
- cap/page: remove auto-issue effect; student requests, admin approves
- learning-panel: admin issue-certificate action per student
- site-settings: contributors editor with avatar upload (ContributorAvatarPicker, TagInput)
- community-panel: render contributors section below social links
- leaderboard-panel: TierBadge, totalParticipants, tier on entries and self
- page.tsx: fix "شروع مسیر" routing to /register instead of /login
- navbar: correct icons (Settings, Palette) in user dropdown
- types: Contributor, LeaderboardTier, Certificate status field, updated LeaderboardData/Entry
- layout: PWA icon metadata (192, 512, apple-touch-icon)

frontend/src/components/navbar.tsx

@@ -2,7 +2,7 @@
 
 import Link from "next/link";
 import { usePathname, useRouter } from "next/navigation";
-import { Flame, Heart, LogOut, Sparkles, User, UserCog } from "lucide-react";
+import { Flame, Heart, LogOut, Palette, Settings, Sparkles, User, UserCog } from "lucide-react";
 import { NotificationBell } from "@/components/notification-bell";
 import { ThemeToggle } from "@/components/theme-toggle";
 import { BrandMark } from "@/components/brand-mark";
@@ -28,7 +28,6 @@ import {
 } from "@/components/ui/dropdown-menu";
 import { Button } from "@/components/ui/button";
 import { cn, formatFaNumber } from "@/lib/utils";
-import { GlobalSearch } from "@/components/global-search";
 import { isVerifiedRole, VerifiedBadge } from "@/components/verified-badge";
 
 const navLinks = [
@@ -65,7 +64,6 @@ export function Navbar() {
             <BrandMark />
           </Link>
           <div className="flex items-center gap-2">
-            <GlobalSearch />
             <ThemeToggle />
             {pathname !== "/login" && (
               <Button asChild size="sm" className="font-bold">
@@ -188,10 +186,10 @@ export function Navbar() {
                     <User /> پروفایل من
                   </DropdownMenuItem>
                   <DropdownMenuItem onClick={() => router.push("/settings")}>
-                    <User /> تنظیمات
+                    <Settings /> تنظیمات
                   </DropdownMenuItem>
                   <DropdownMenuItem onSelect={() => setStudioOpen(true)}>
-                    <User /> ویرایش آواتار
+                    <Palette /> ویرایش آواتار
                   </DropdownMenuItem>
                   {liveUser.role === "admin" && (
                     <DropdownMenuItem onClick={() => router.push("/admin")}>