fix: use Vite API directly for global CLI

Spawn-based approach fails on global install because node_modules
is hoisted. Use programmatic Vite API instead. Move vite, plugin-vue,
and sass to dependencies so they're available at runtime.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bin/hermes-web-ui.mjs

@@ -1,22 +1,36 @@
 #!/usr/bin/env node
-import { spawn } from 'child_process'
 import { resolve, dirname } from 'path'
 import { fileURLToPath } from 'url'
 
 const __dirname = dirname(fileURLToPath(import.meta.url))
 const projectRoot = resolve(__dirname, '..')
 
-const args = process.argv.slice(2)
-const command = args[0]
+const command = process.argv[2]
 
 if (!command || command === 'start' || command === 'dev') {
-  const viteBin = resolve(projectRoot, 'node_modules/.bin/vite')
-  spawn(viteBin, ['--host', '--port', '8648'], { stdio: 'inherit', cwd: projectRoot })
+  const { createServer } = await import('vite')
+  const vue = await import('@vitejs/plugin-vue')
+  const server = await createServer({
+    root: projectRoot,
+    configFile: resolve(projectRoot, 'vite.config.ts'),
+    server: {
+      host: true,
+      port: 8648,
+    },
+    plugins: [vue.default()],
+  })
+  await server.listen()
+  server.printUrls()
 } else if (command === 'build') {
-  const viteBin = resolve(projectRoot, 'node_modules/.bin/vite')
-  spawn(viteBin, ['build'], { stdio: 'inherit', cwd: projectRoot })
+  const { build } = await import('vite')
+  const vue = await import('@vitejs/plugin-vue')
+  await build({
+    root: projectRoot,
+    configFile: resolve(projectRoot, 'vite.config.ts'),
+    plugins: [vue.default()],
+  })
 } else {
-  console.log(`Usage: hermes-web-ui [command]`)
+  console.log('Usage: hermes-web-ui [command]')
   console.log()
   console.log('Commands:')
   console.log('  start    Start dev server (default)')