Add urapt-web: web UI for urapt-server instances

A Vite + React 18 + TypeScript SPA, same-origin with the API (no CORS,
no Go server changes). Full management parity with the urapt CLI:

- First-run setup (admin bootstrap via needs_setup), login/logout
- Repositories: list, create, tabbed detail (overview edit/delete,
  members CRUD, distributions/components/architectures manager,
  package list + .deb upload + detail + delete, apt-config panel)
- API tokens: show-once creation + revoke
- Admin users: toggle admin / delete
- Settings + dark mode

Stack: Tailwind + shadcn/ui (New York), React Router v7 (lazy routes),
TanStack Query v5, Zustand, Vitest. Hand-written typed API client
mirroring shared/api + shared/models. Dev proxy forwards /api + /apt
to a local urapt-server; deploy behind nginx/Caddy (see urapt-web/README).

urapt-web/components.json

@@ -0,0 +1,21 @@
+{
+  "$schema": "https://ui.shadcn.com/schema.json",
+  "style": "new-york",
+  "rsc": false,
+  "tsx": true,
+  "tailwind": {
+    "config": "tailwind.config.js",
+    "css": "src/index.css",
+    "baseColor": "neutral",
+    "cssVariables": true,
+    "prefix": ""
+  },
+  "aliases": {
+    "components": "@/components",
+    "utils": "@/lib/utils",
+    "ui": "@/components/ui",
+    "lib": "@/lib",
+    "hooks": "@/hooks"
+  },
+  "iconLibrary": "lucide"
+}