web: scaffold Vue 3 + Vite app (create-vue, lean options)

Verbatim output of 'npm create vue@latest web -- --ts --vitest
--eslint --prettier' so this commit shows exactly what the official
scaffold generates; our own changes come separately. Lean per the
agreed choices: no Router/Pinia until a second page or shared state
exists. node_modules is ignored via the scaffold's own web/.gitignore.

web/vite.config.ts

@@ -0,0 +1,18 @@
+import { fileURLToPath, URL } from 'node:url'
+
+import { defineConfig } from 'vite'
+import vue from '@vitejs/plugin-vue'
+import vueDevTools from 'vite-plugin-vue-devtools'
+
+// https://vite.dev/config/
+export default defineConfig({
+  plugins: [
+    vue(),
+    vueDevTools(),
+  ],
+  resolve: {
+    alias: {
+      '@': fileURLToPath(new URL('./src', import.meta.url))
+    },
+  },
+})