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/community-panel.tsx

@@ -1,17 +1,50 @@
 "use client";
 
 import { useQuery } from "@tanstack/react-query";
-import { ExternalLink, Share2 } from "lucide-react";
+import { ExternalLink, Share2, Tag, Users } from "lucide-react";
 import { http, toUserError } from "@/lib/api";
 import { Panel } from "@/components/panel";
 import { Button } from "@/components/ui/button";
+import { Badge } from "@/components/ui/badge";
+import type { Contributor } from "@/lib/types";
 
 export type SocialLink = { name: string; url: string };
 
 export type CommunityPayload = {
   socials: SocialLink[];
+  contributors: Contributor[];
 };
 
+function ContributorAvatar({ contributor }: { contributor: Contributor }) {
+  if (contributor.avatar) {
+    return (
+      <img
+        src={contributor.avatar}
+        alt={contributor.name}
+        className="h-12 w-12 shrink-0 rounded-full border-2 border-border object-cover"
+        onError={(e) => {
+          (e.currentTarget as HTMLImageElement).style.display = "none";
+          (e.currentTarget.nextElementSibling as HTMLElement | null)?.removeAttribute("hidden");
+        }}
+      />
+    );
+  }
+  const initials = contributor.name
+    .split(" ")
+    .map((w) => w[0])
+    .slice(0, 2)
+    .join("")
+    .toUpperCase();
+  return (
+    <span
+      aria-hidden
+      className="flex h-12 w-12 shrink-0 items-center justify-center rounded-full border-2 border-border bg-primary/10 text-sm font-bold text-primary"
+    >
+      {initials}
+    </span>
+  );
+}
+
 export function CommunityPanel() {
   const { data, isLoading, isError, error, refetch } = useQuery({
     queryKey: ["community"],
@@ -19,12 +52,17 @@ export function CommunityPanel() {
   });
 
   if (isLoading) {
-    return <div className="h-72 animate-pulse rounded-2xl border-2 border-border bg-muted/40" />;
+    return (
+      <div className="mx-auto max-w-2xl space-y-4">
+        <div className="h-40 animate-pulse rounded-2xl border-2 border-border bg-muted/40" />
+        <div className="h-64 animate-pulse rounded-2xl border-2 border-border bg-muted/40" />
+      </div>
+    );
   }
 
   if (isError) {
     return (
-      <div className="mx-auto max-w-xl rounded-2xl border-2 border-destructive/30 bg-destructive/5 p-8 text-center">
+      <div className="mx-auto max-w-2xl rounded-2xl border-2 border-destructive/30 bg-destructive/5 p-8 text-center">
         <p className="font-medium text-destructive">{toUserError(error)}</p>
         <Button className="mt-4" variant="outline" onClick={() => refetch()}>
           تلاش دوباره
@@ -34,9 +72,11 @@ export function CommunityPanel() {
   }
 
   const socials = data?.socials ?? [];
+  const contributors = data?.contributors ?? [];
 
   return (
-    <div className="mx-auto max-w-xl">
+    <div className="mx-auto max-w-2xl space-y-4">
+      {/* Social links */}
       <Panel
         title="شبکه‌های پرگار"
         description="راه‌های رسمی ارتباط با برنامه. لینک شخصی هر کاربر روی پروفایل خودش است."
@@ -63,6 +103,61 @@ export function CommunityPanel() {
           </ul>
         )}
       </Panel>
+
+      {/* Contributors */}
+      <Panel
+        title="مشارکت‌کنندگان"
+        description="افرادی که در ساخت پرگار سهیم بوده‌اند. ممنون از هر کمکی."
+        icon={<Users className="h-5 w-5" />}
+        tint="bg-emerald-500/15 text-emerald-600 dark:text-emerald-400"
+      >
+        {contributors.length === 0 ? (
+          <p className="py-8 text-center text-sm text-muted-foreground">اطلاعات مشارکت‌کنندگان هنوز ثبت نشده است.</p>
+        ) : (
+          <ul className="divide-y divide-border/60">
+            {contributors.map((c, i) => (
+              <li key={i} className="flex flex-col gap-3 py-4 first:pt-0 last:pb-0 sm:flex-row sm:items-start">
+                <ContributorAvatar contributor={c} />
+                <div className="min-w-0 flex-1 space-y-1.5">
+                  <div className="flex flex-wrap items-center gap-2">
+                    {c.url ? (
+                      <a
+                        href={c.url}
+                        target="_blank"
+                        rel="noreferrer"
+                        className="flex items-center gap-1 font-bold hover:text-primary hover:underline"
+                      >
+                        {c.name}
+                        <ExternalLink className="h-3 w-3 shrink-0 text-muted-foreground" />
+                      </a>
+                    ) : (
+                      <span className="font-bold">{c.name}</span>
+                    )}
+                    {c.role && (
+                      <span className="text-xs text-muted-foreground">{c.role}</span>
+                    )}
+                  </div>
+                  {c.bio && <p className="text-sm leading-relaxed text-muted-foreground">{c.bio}</p>}
+                  {c.contributions.length > 0 && (
+                    <div className="flex flex-wrap gap-1.5">
+                      {c.contributions.map((cat) => (
+                        <Badge
+                          key={cat}
+                          variant="secondary"
+                          className="gap-1 px-2 py-0.5 text-xs"
+                        >
+                          <Tag className="h-3 w-3" />
+                          {cat}
+                        </Badge>
+                      ))}
+                    </div>
+                  )}
+                </div>
+              </li>
+            ))}
+          </ul>
+        )}
+      </Panel>
     </div>
   );
 }