feat(adminsite): scaffold and site/'s token system

A fifth Next.js app, built like web/ and site/: App Router, React 18,
Tailwind 3, TanStack Query, standalone output.

app/globals.css carries site/app/globals.css's token blocks copied verbatim
rather than retyped, so the two cannot drift by transcription. Tailwind holds
var() references only -- no component or config entry may contain a hex
value. The semantic three are aliased: site/'s --up/--pend/--down become
valid/warn/expired, so each app names the colours for what it shows.

Unlike web/, there is no rewrite proxy: the browser calls admin directly, so
NEXT_PUBLIC_ADMIN_API_URL must be browser-reachable and listed in admin's
ADMIN_ORIGIN.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

adminsite/tsconfig.json

@@ -0,0 +1,22 @@
+{
+    "compilerOptions": {
+        "target": "ES2022",
+        "lib": ["dom", "dom.iterable", "esnext"],
+        "allowJs": false,
+        "skipLibCheck": true,
+        "strict": true,
+        "noEmit": true,
+        "esModuleInterop": true,
+        "module": "esnext",
+        "moduleResolution": "bundler",
+        "resolveJsonModule": true,
+        "isolatedModules": true,
+        "jsx": "preserve",
+        "incremental": true,
+        "types": ["vitest/globals", "@testing-library/jest-dom"],
+        "plugins": [{ "name": "next" }],
+        "paths": { "@/*": ["./*"] }
+    },
+    "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+    "exclude": ["node_modules"]
+}