feat: implement 8 features across full stack

- Leaderboard: rank-based percentile tiers (champion/gold/silver/bronze),
    deterministic tie-breaking (xp DESC, user_id ASC)
  - Mentor chat: md: breakpoints, safe-area-inset-bottom padding
  - Learning progress: server-side progressPct, curriculum expansion safety
  - Physical orders: hard-disabled with 410 Gone
  - Certificate approval: pending/issued flow, admin issue/revoke endpoints,
    certificate_requires_approval setting (migration 0031)
  - Draft/publish: is_published on lessons and chapters, admin publish UI
    (migration 0030)
  - Video panel: static thumbnails (no preload), client-side pagination
  - Rich editor: TipTap + tiptap-markdown for lesson descriptions,
    marked + DOMPurify for SafeMarkdown rendering

frontend/src/components/profile-certificate-slot.tsx

@@ -3,18 +3,17 @@
 import { useEffect, useRef, useState } from "react";
 import { useRouter } from "next/navigation";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
-import { Award, Copy, ExternalLink, Loader2, Lock, Package } from "lucide-react";
+import { Award, Clock, Copy, ExternalLink, Loader2, Lock } from "lucide-react";
 import { http, toUserError } from "@/lib/api";
-import type { Certificate, CertificatePhysicalOrder, PhysicalCertSettings } from "@/lib/types";
+import type { Certificate, CertificatePhysicalOrder } from "@/lib/types";
 import { Button } from "@/components/ui/button";
 import { toast } from "@/components/providers";
-import { cn, formatFaNumber } from "@/lib/utils";
+import { cn } from "@/lib/utils";
 
 type MineCertificateResponse = {
   certificate: Certificate | null;
   eligible: boolean;
   physicalOrder: CertificatePhysicalOrder | null;
-  physical: PhysicalCertSettings;
 };
 
 const ORDER_LABEL: Record<string, string> = {
@@ -37,7 +36,6 @@ export function ProfileCertificateSlot() {
 
   const cert = data?.certificate ?? null;
   const eligible = !!data?.eligible;
-  const physical = data?.physical;
   const order = data?.physicalOrder;
 
   // Auto-issue once when the student becomes eligible (same path as /cap).
@@ -83,14 +81,6 @@ export function ProfileCertificateSlot() {
     }
   };
 
-  const physicalOpen =
-    !!physical?.enabled &&
-    !!cert &&
-    (!order || order.status === "cancelled") &&
-    (!cert.issuedAt ||
-      Date.now() <
-        new Date(cert.issuedAt).getTime() + (physical.windowDays || 30) * 24 * 60 * 60 * 1000);
-
   return (
     <section
       aria-label="جایگاه گواهینامه"
@@ -118,7 +108,17 @@ export function ProfileCertificateSlot() {
           <Loader2 className="h-3.5 w-3.5 animate-spin" />
           در حال بارگذاری…
         </div>
-      ) : cert ? (
+      ) : cert?.status === "pending" ? (
+        <div className="flex items-start gap-2 rounded-lg border border-border/70 bg-background/60 px-3 py-2.5">
+          <Clock className="mt-0.5 h-3.5 w-3.5 shrink-0 text-warning" />
+          <div>
+            <p className="text-[11px] font-bold text-foreground">در انتظار تأیید</p>
+            <p className="mt-0.5 text-[10px] leading-relaxed text-muted-foreground">
+              درخواست گواهینامه ثبت شد و پس از بررسی توسط تیم آموزش صادر می‌شود.
+            </p>
+          </div>
+        </div>
+      ) : cert?.status === "issued" && cert.publicId ? (
         <div className="space-y-2.5">
           <div className="rounded-lg border border-primary/25 bg-primary/5 px-3 py-2.5">
             <p className="text-sm font-bold text-foreground">{cert.fullName}</p>
@@ -129,12 +129,6 @@ export function ProfileCertificateSlot() {
               {cert.publicId}
             </p>
           </div>
-          {order && order.status !== "cancelled" ? (
-            <p className="text-[11px] font-medium text-muted-foreground">
-              {ORDER_LABEL[order.status] ?? order.status}
-              {order.trackingCode ? ` · کد پیگیری ${order.trackingCode}` : ""}
-            </p>
-          ) : null}
           <div className="flex flex-wrap gap-1.5">
             <Button type="button" size="sm" className="h-8 flex-1" onClick={openCert}>
               <ExternalLink className="h-3.5 w-3.5" />
@@ -144,12 +138,6 @@ export function ProfileCertificateSlot() {
               <Copy className="h-3.5 w-3.5" />
               کپی لینک
             </Button>
-            {physicalOpen ? (
-              <Button type="button" size="sm" variant="outline" className="h-8" onClick={openCert}>
-                <Package className="h-3.5 w-3.5" />
-                فیزیکی
-              </Button>
-            ) : null}
           </div>
         </div>
       ) : eligible ? (
@@ -172,10 +160,7 @@ export function ProfileCertificateSlot() {
           <div>
             <p className="text-[11px] font-bold text-foreground">هنوز صادر نشده</p>
             <p className="mt-0.5 text-[10px] leading-relaxed text-muted-foreground">
-              با پاس کردن همه درس‌های فعال، گواهینامه همین‌جا نمایش داده می‌شود
-              {physical?.enabled
-                ? `؛ در صورت فعال بودن، نسخه فیزیکی (پرداخت آفلاین) تا ${formatFaNumber(physical.windowDays)} روز پس از صدور قابل درخواست است.`
-                : "."}
+              با پاس کردن همه درس‌های فعال، گواهینامه همین‌جا نمایش داده می‌شود.
             </p>
           </div>
         </div>