feat(remotion): player default demo = IG promo (bare /player/ URL renders it)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/remotion/player/main.tsx

@@ -25,6 +25,19 @@ interface PlayerInput {
   watermark?: boolean;
 }
 
+// Asset-free demo shown when opened with no scene data (so the bare /player/ URL
+// renders something real to test the in-browser engine).
+const DEFAULT_DEMO = {
+  scenes: [
+    { blockId: "IGIntro", durationSec: 3, props: { badge: "اینستاگرام", headline: "صفحهٔ ما را دنبال کنید", subtitle: "هر روز یک طرح تازه" } },
+    { blockId: "IGProfile", durationSec: 5, props: { headline: "صفحهٔ ما را دنبال کنید", handle: "flat.studio", name: "استودیو فلت", category: "هنر و طراحی", bio1: "هر روز یک طرح تازه ✨", bio2: "آموزش، قالب و الهام برای طراحان", bio3: "سفارش و دانلود 👇", link: "flat.studio/shop", posts: "۳۲۰", followers: "۲۴٫۸ هزار", following: "۱۸۰", hi1: "جدید", hi2: "قالب‌ها", hi3: "آموزش", hi4: "نمونه‌کار", followLabel: "دنبال کردن", messageLabel: "پیام" } },
+    { blockId: "IGFeed", durationSec: 4, props: { caption: "محتوای ما را ببینید" } },
+    { blockId: "IGStats", durationSec: 3, props: { bigValue: "۲۴۸۰۰", bigLabel: "دنبال‌کننده", stat2Value: "۱۲۰۰۰۰۰", stat2Label: "پسند", stat3Value: "۳۲۰", stat3Label: "پست", proofLine: "به جمع هزاران دنبال‌کنندهٔ ما بپیوندید" } },
+    { blockId: "IGFollowCTA", durationSec: 3, props: { headline: "همین حالا دنبال کنید", handle: "@flat.studio", buttonLabel: "دنبال کردن", followedLabel: "دنبال شد", footer: "لینک در بایو 👆" } },
+  ],
+  accentColor: "#dc2743", secondaryColor: "#7c5cff", backgroundColor: "#f7f4fa", textColor: "#15151a", music: "", sfx: false, finish: false,
+} as unknown as typeof flexStoryDefaults;
+
 function decodeHash(): PlayerInput | null {
   try {
     const h = window.location.hash.replace(/^#/, "");
@@ -78,7 +91,7 @@ const App: React.FC = () => {
     return () => window.removeEventListener("message", onMsg);
   }, []);
 
-  const props = input?.props ?? flexStoryDefaults;
+  const props = input?.props ?? DEFAULT_DEMO;
   const aspect = (input?.aspect ?? "9:16") as keyof typeof ASPECTS;
   const [w, h] = ASPECTS[aspect] ?? ASPECTS["9:16"];
   const watermark = input?.watermark ?? true;