refactor(web): switch to Bun + Nitro v2 (bun preset) — proper TanStack Start deploy

The earlier "render the shell with a custom script" was a hack. The real issues were a
version matrix and a missing server target:

- TanStack Start's start-plugin-core peer-requires Vite >= 7; on Vite 6 the build's
  prerender/post-build buildApp plugin hook silently doesn't run (Vite 6 lets a
  config-level builder.buildApp suppress plugin buildApp hooks; Vite 7 runs both). Pinned
  Vite ^7 + @vitejs/plugin-react ^5 (v5 ↔ Vite 7; v6 needs Vite 8 / vite/internal).
- Added @tanstack/nitro-v2-vite-plugin with the `bun` preset — the server/deploy target.
  `bun run build` → .output/ (bun-runnable server + .output/public). `bun run start` =
  `bun run .output/server/index.mjs`.
- Full SSR instead of SPA mode: SPA-shell prerender points its preview server at the old
  dist/server/server.js path that Nitro relocates, breaking the build. The Nitro server
  renders the shell per request; React Query fetches client-side after hydration.
- Nitro routeRules proxy /api/** → PUNKTFUNK_MGMT_URL (default 127.0.0.1:47990), so the
  browser stays same-origin (bearer token rides along, no CORS).

Toolchain is now Bun (package manager + runtime): bun.lock replaces pnpm-lock.yaml;
scripts/prepare/start use bun. Validated live: bun build → .output, bun server SSR-renders
the console on :3000 and proxies the API (health/host return through it). tsc clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/package.json

@@ -4,13 +4,13 @@
   "type": "module",
   "description": "punktfunk management console — TanStack Start + React Query (orval) + shadcn/ui + Paraglide i18n",
   "scripts": {
-    "prepare": "pnpm run codegen",
+    "prepare": "bun run codegen",
     "codegen": "orval --config orval.config.ts && paraglide-js compile --project ./project.inlang --outdir ./src/paraglide",
     "predev": "orval --config orval.config.ts",
     "dev": "vite dev --port 3000",
     "prebuild": "orval --config orval.config.ts",
     "build": "vite build",
-    "start": "node .output/server/index.mjs",
+    "start": "bun run .output/server/index.mjs",
     "api:gen": "orval --config orval.config.ts",
     "lint": "tsc --noEmit"
   },
@@ -28,15 +28,16 @@
   "devDependencies": {
     "@inlang/paraglide-js": "^2.0.0",
     "@tailwindcss/vite": "^4.0.0",
+    "@tanstack/nitro-v2-vite-plugin": "^1.155.0",
     "@types/node": "^22.10.0",
     "@types/react": "^19.0.0",
     "@types/react-dom": "^19.0.0",
-    "@vitejs/plugin-react": "^4.7.0",
+    "@vitejs/plugin-react": "^5",
     "orval": "^8.16.0",
     "tailwindcss": "^4.0.0",
     "tw-animate-css": "^1.2.0",
     "typescript": "^5.7.0",
-    "vite": "^6.0.0",
+    "vite": "^7.3.5",
     "vite-tsconfig-paths": "^5.1.0"
   }
 }