feat(remotion): premium 3D app-showcase template (AppShowcase3D)

- New @remotion/three template: titanium flagship phone (thin rim, glossy black
  glass, rounded-corner screen via ShapeGeometry, dynamic island, side buttons),
  light keynote studio (contact shadow + env reflections + DOF + soft bloom),
  film grain + entrance light-sweep. All 3 aspects re-flowed.
- Editable screenUrl (user app screenshot textured onto the screen via TextureLoader
  + delayRender), appName/tagline/cta, 4 colours (dark text on light bg).
- Add pick(wide,square,tall) helper to lib/aspect.ts (Tier-0 from the R&D).
- Seed: AppShowcase3D + per-template text colour; built with the flat-artist skill.

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

services/remotion/src/templates.tsx

@@ -24,6 +24,7 @@ import { Hero3D, hero3DSchema } from "./compositions/Hero3D";
 import { Nowruz3D, nowruz3DSchema } from "./compositions/Nowruz3D";
 import { Birthday3D, birthday3DSchema } from "./compositions/Birthday3D";
 import { Promo3D, promo3DSchema } from "./compositions/Promo3D";
+import { AppShowcase3D, appShowcase3DSchema } from "./compositions/AppShowcase3D";
 
 export interface TemplateDef {
   /** Base id; the registered composition ids are `${id}-${aspect}`. */
@@ -232,4 +233,22 @@ export const TEMPLATES: TemplateDef[] = [
       textColor: "#ffffff",
     },
   },
+  {
+    id: "AppShowcase3D",
+    name: "معرفی اپلیکیشن سه‌بعدی",
+    description: "نمایش سه‌بعدی و حرفه‌ای اپلیکیشن روی گوشی پرچم‌دار با نورپردازی استودیویی",
+    component: AppShowcase3D,
+    schema: appShowcase3DSchema,
+    durationSec: 6,
+    defaultProps: {
+      appName: "اپلیکیشن شما",
+      tagline: "تجربه‌ای روان، سریع و زیبا",
+      cta: "همین حالا دانلود کنید",
+      screenUrl: "",
+      accentColor: "#3b82f6",
+      secondaryColor: "#8b5cf6",
+      backgroundColor: "#f4f5f7",
+      textColor: "#0f172a",
+    },
+  },
 ];