feat(render+admin): exports management (all users' rendered videos)

- render-svc: admin-scoped store (ListAllExports / GetExportByIDAny /
  SoftDeleteExportAny) + GET/DELETE/download-url under /v1/admin-exports
  (admin-gated; separate prefix so it routes to render, not identity's /admin)
- gateway: /v1/admin-exports/* → render
- admin /admin/exports: paginated table of every rendered export with thumbnail,
  type/quality, size, duration, dimensions, produce + expiry dates; download
  (presigned URL) and delete

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

messages/en.json

@@ -335,7 +335,8 @@
       "routes": "Internal Routes",
       "integrations": "Integrations",
       "projects": "Projects",
-      "nodeFonts": "Node Fonts"
+      "nodeFonts": "Node Fonts",
+      "exports": "Exports"
     },
     "appAdminNodesPage": {
       "title": "Render Nodes",

messages/fa.json

@@ -335,7 +335,8 @@
       "routes": "مسیرهای داخلی",
       "integrations": "یکپارچه‌سازی‌ها",
       "projects": "پروژه‌ها",
-      "nodeFonts": "فونت نودها"
+      "nodeFonts": "فونت نودها",
+      "exports": "خروجی‌های رندر"
     },
     "appAdminNodesPage": {
       "title": "نودهای رندر",