Add VitePress site with local login and deployment docs

Enable static site build on port 12100 with Express session auth, auto sidebar, and DEPLOY.md for Ubuntu/NPS setup.

Co-authored-by: Cursor <cursoragent@cursor.com>

.vitepress/missing-assets-plugin.mjs

@@ -0,0 +1,49 @@
+import fs from 'node:fs'
+import path from 'node:path'
+
+const assetPattern = /\.(png|jpe?g|gif|webp|svg|bmp)(\?.*)?$/i
+
+function toPublicUrl(source) {
+  if (source.startsWith('../images/')) {
+    return `/images/${source.slice('../images/'.length)}`
+  }
+  if (source.startsWith('../assets/')) {
+    return `/assets/${source.slice('../assets/'.length)}`
+  }
+  if (source.startsWith('images/')) {
+    return `/images/${source.slice('images/'.length)}`
+  }
+  if (source.startsWith('assets/')) {
+    return `/assets/${source.slice('assets/'.length)}`
+  }
+  return `/${source.replace(/^\.\//, '')}`
+}
+
+export function missingAssetsPlugin() {
+  return {
+    name: 'vitepress-missing-assets',
+    enforce: 'pre',
+    resolveId(source, importer) {
+      if (!importer?.endsWith('.md') || !assetPattern.test(source)) {
+        return null
+      }
+      if (/^https?:\/\//.test(source)) {
+        return null
+      }
+
+      const resolved = path.resolve(path.dirname(importer), source)
+      if (fs.existsSync(resolved)) {
+        return null
+      }
+
+      return `\0missing-asset:${toPublicUrl(source)}`
+    },
+    load(id) {
+      if (!id.startsWith('\0missing-asset:')) {
+        return null
+      }
+      const url = id.slice('\0missing-asset:'.length)
+      return `export default ${JSON.stringify(url)}`
+    },
+  }
+}