WP-00: project skeleton with three-level test harness

Cargo workspace (domain, application, infrastructure, api), axum health endpoint
with SPA fallback, Vue 3 + Tailwind frontend, Vitest, Playwright, Makefile,
Gitea Actions CI and README.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

frontend/vite.config.ts

@@ -0,0 +1,18 @@
+/// <reference types="vitest/config" />
+import { defineConfig } from 'vite'
+import vue from '@vitejs/plugin-vue'
+import tailwindcss from '@tailwindcss/vite'
+
+export default defineConfig({
+  plugins: [vue(), tailwindcss()],
+  server: {
+    host: '127.0.0.1',
+    port: 5173,
+    proxy: { '/api': 'http://127.0.0.1:8080', '/healthz': 'http://127.0.0.1:8080' },
+  },
+  test: {
+    environment: 'jsdom',
+    include: ['src/**/*.test.ts'],
+    globals: true,
+  },
+})