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/app/c/[id]/page.tsx

@@ -1,45 +1,23 @@
 "use client";
 
-import { useQuery, useQueryClient } from "@tanstack/react-query";
+import { useQuery } from "@tanstack/react-query";
 import { useParams } from "next/navigation";
-import { Loader2, Package } from "lucide-react";
+import { Loader2 } from "lucide-react";
 import { CertificateCard } from "@/components/certificate-card";
 import { NotFoundState, notFoundSentence } from "@/components/not-found-state";
-import { Button } from "@/components/ui/button";
-import { Input } from "@/components/ui/input";
 import { http, toUserError } from "@/lib/api";
 import { useAuth } from "@/lib/auth-store";
-import type { Certificate, CertificatePhysicalOrder, PhysicalCertSettings } from "@/lib/types";
-import { toast } from "@/components/providers";
-import { formatFaNumber } from "@/lib/utils";
-import { clampPhoneInput, normalizePhone, PHONE_INPUT_MAX_LEN } from "@/lib/validation";
-import { useEffect, useState } from "react";
+import type { Certificate } from "@/lib/types";
 
 type PublicCertResponse = {
   certificate: { publicId: string; fullName: string; issuedAt: string };
   course: string;
 };
 
-const STATUS_LABEL: Record<string, string> = {
-  requested: "درخواست‌شده — منتظر تأیید پرداخت",
-  paid: "پرداخت تأیید شد — در صف ارسال",
-  shipped: "ارسال شد",
-  cancelled: "لغو شده",
-};
-
 export default function CertificatePage() {
   const params = useParams<{ id: string }>();
   const publicId = params?.id ?? "";
   const authUser = useAuth((s) => s.user);
-  const qc = useQueryClient();
-  const [requesting, setRequesting] = useState(false);
-  const [form, setForm] = useState({
-    recipientName: "",
-    phone: "",
-    address: "",
-    city: "",
-    postalCode: "",
-  });
 
   const { data, isLoading, error } = useQuery({
     queryKey: ["certificate", publicId],
@@ -50,42 +28,12 @@ export default function CertificatePage() {
 
   const { data: mine } = useQuery({
     queryKey: ["me", "certificate"],
-    queryFn: () =>
-      http.get<{
-        certificate: Certificate | null;
-        physicalOrder: CertificatePhysicalOrder | null;
-        physical: PhysicalCertSettings;
-      }>("/api/me/certificate"),
+    queryFn: () => http.get<{ certificate: Certificate | null }>("/api/me/certificate"),
     enabled: !!authUser,
   });
 
   const isOwner = !!authUser && mine?.certificate?.publicId === publicId;
 
-  useEffect(() => {
-    if (!isOwner || !authUser) return;
-    setForm((f) => ({
-      ...f,
-      recipientName: f.recipientName || authUser.name || "",
-      phone: f.phone || authUser.phone || "",
-    }));
-  }, [isOwner, authUser]);
-
-  const requestPhysical = async () => {
-    setRequesting(true);
-    try {
-      await http.post("/api/me/certificate/physical", {
-        ...form,
-        phone: normalizePhone(form.phone),
-      });
-      toast.success("درخواست ثبت شد — پس از واریز با ادمین هماهنگ کنید");
-      qc.invalidateQueries({ queryKey: ["me", "certificate"] });
-    } catch (e) {
-      toast.error(toUserError(e));
-    } finally {
-      setRequesting(false);
-    }
-  };
-
   if (isLoading) {
     return (
       <div className="flex min-h-[60vh] items-center justify-center">
@@ -110,17 +58,6 @@ export default function CertificatePage() {
   }
 
   const cert = data.certificate;
-  const order = isOwner ? mine?.physicalOrder : null;
-  const physical = isOwner ? mine?.physical : null;
-  const windowEndsAt = mine?.certificate?.issuedAt
-    ? new Date(mine.certificate.issuedAt).getTime() + (physical?.windowDays ?? 30) * 86400000
-    : 0;
-  const windowStillOpen = !windowEndsAt || Date.now() < windowEndsAt;
-  const windowOpen =
-    physical?.enabled &&
-    windowStillOpen &&
-    (!order || order.status === "cancelled") &&
-    !!mine?.certificate;
 
   return (
     <CertificateCard
@@ -130,94 +67,7 @@ export default function CertificatePage() {
         issuedAt: cert.issuedAt,
         course: data.course,
       }}
-      showOwnerLinks={!!authUser}
-    >
-      {isOwner && physical?.enabled && (
-        <div className="mt-8 space-y-3 border-t border-border pt-6">
-          <p className="flex items-center gap-2 text-sm font-bold">
-            <Package className="h-4 w-4" /> نسخه فیزیکی
-          </p>
-          <p className="text-xs text-muted-foreground">
-            قیمت حدودی {formatFaNumber(physical.priceIrr)} ریال · مهلت درخواست{" "}
-            {formatFaNumber(physical.windowDays)} روز از صدور
-            {windowEndsAt ? ` (تا ${new Date(windowEndsAt).toLocaleDateString("fa-IR")})` : ""}.
-            پرداخت آنلاین در سامانه نداریم. پس از واریز بیرونی با ادمین هماهنگ کنید تا وضعیت سفارش به‌روز شود.
-          </p>
-          {order && order.status !== "cancelled" ? (
-            <div className="space-y-2 rounded-xl border border-border bg-muted/30 p-3 text-sm">
-              <p>
-                وضعیت: <span className="font-medium">{STATUS_LABEL[order.status] ?? order.status}</span>
-              </p>
-              {order.trackingCode && (
-                <p className="font-mono text-xs" dir="ltr">
-                  کد پیگیری: {order.trackingCode}
-                </p>
-              )}
-              {order.city && (
-                <p className="text-xs text-muted-foreground">
-                  ارسال به {order.recipientName || "—"} · {order.city}
-                </p>
-              )}
-              {order.note && <p className="text-xs text-muted-foreground">یادداشت ادمین: {order.note}</p>}
-              <Button
-                size="sm"
-                variant="outline"
-                onClick={() =>
-                  window.dispatchEvent(new CustomEvent("pargar:chat", { detail: { open: true } }))
-                }
-              >
-                هماهنگی با تیم
-              </Button>
-            </div>
-          ) : windowOpen ? (
-            <div className="space-y-2">
-              <div className="grid gap-2 sm:grid-cols-2">
-                <Input
-                  placeholder="نام گیرنده"
-                  value={form.recipientName}
-                  onChange={(e) => setForm((f) => ({ ...f, recipientName: e.target.value }))}
-                />
-                <Input
-                  placeholder="موبایل"
-                  value={form.phone}
-                  onChange={(e) => setForm((f) => ({ ...f, phone: clampPhoneInput(e.target.value) }))}
-                  dir="ltr"
-                  inputMode="tel"
-                  maxLength={PHONE_INPUT_MAX_LEN}
-                  className="text-left"
-                />
-                <Input
-                  placeholder="شهر"
-                  value={form.city}
-                  onChange={(e) => setForm((f) => ({ ...f, city: e.target.value }))}
-                />
-                <Input
-                  placeholder="کد پستی"
-                  value={form.postalCode}
-                  onChange={(e) => setForm((f) => ({ ...f, postalCode: e.target.value }))}
-                  dir="ltr"
-                />
-              </div>
-              <textarea
-                className="min-h-[72px] w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
-                placeholder="آدرس کامل پستی"
-                value={form.address}
-                onChange={(e) => setForm((f) => ({ ...f, address: e.target.value }))}
-              />
-              <Button
-                size="sm"
-                disabled={requesting || !form.address.trim() || !form.city.trim()}
-                onClick={() => void requestPhysical()}
-              >
-                {requesting ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <Package className="h-3.5 w-3.5" />}
-                ثبت درخواست نسخه فیزیکی
-              </Button>
-            </div>
-          ) : !windowStillOpen ? (
-            <p className="text-sm text-muted-foreground">مهلت درخواست نسخه فیزیکی به پایان رسیده است.</p>
-          ) : null}
-        </div>
-      )}
-    </CertificateCard>
+      showOwnerLinks={isOwner}
+    />
   );
 }