feat(admin): standalone Projects page + per-project asset manager

- content-svc: GET /v1/projects (browse/search all projects across containers,
  paginated, admin) returning template name/slug + AE status; project_assets
  table (mig 23) + entity; GET/POST/DELETE /v1/projects/{id}/assets
- /admin/projects: searchable, paginated list of every renderable project with
  thumbnail, template, aspect/resolution, AE-file + publish status
- ProjectAssets component: list/upload/delete named footage/image/audio/font
  files per project (reused in the projects page; AE file upload alongside)
- nav + fa/en "Projects" label

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

src/app/[locale]/admin/layout.tsx

@@ -19,6 +19,7 @@ export default async function AdminLayout({
     { href: "/admin/stats", label: t("stats") },
     { href: "/admin/categories", label: t("categories") },
     { href: "/admin/templates", label: t("templates") },
+    { href: "/admin/projects", label: t("projects") },
     { href: "/admin/ranking", label: t("ranking") },
     { href: "/admin/tags", label: t("tags") },
     { href: "/admin/fonts", label: t("fonts") },