docs: add Vercel deploy config

Vercel build uses npm rather than the pnpm comux uses, because
Vercel's bundled pnpm hits ERR_INVALID_THIS on Node 22+ and the
packageManager field alone doesn't trigger corepack on first
install (no lockfile committed). npm install --ignore-scripts
runs cleanly in ~28s.

packageManager pinned for local pnpm consistency; install/build
commands in vercel.json drive the actual deploy.

Currently deployed at https://docs-0xbuns.vercel.app (0xBuns
scope on Vercel; buns-projects scope is at the 200-project
Hobby cap).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: BunsDev

docs/package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "private": true,
   "type": "module",
+  "packageManager": "pnpm@9.15.4",
   "scripts": {
     "dev": "vite dev",
     "build": "vite build && rm -rf client && cp -R src/dist/client client",

docs/vercel.json

@@ -0,0 +1,11 @@
+{
+  "buildCommand": "npm run build",
+  "outputDirectory": "client",
+  "installCommand": "npm install --ignore-scripts",
+  "rewrites": [
+    {
+      "source": "/(.*)",
+      "destination": "/index.html"
+    }
+  ]
+}