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/eslint.config.js

@@ -0,0 +1,9 @@
+import pluginVue from 'eslint-plugin-vue'
+import { defineConfigWithVueTs, vueTsConfigs } from '@vue/eslint-config-typescript'
+
+export default defineConfigWithVueTs(
+  { ignores: ['dist/**', 'node_modules/**', 'playwright-report/**', 'test-results/**'] },
+  pluginVue.configs['flat/essential'],
+  vueTsConfigs.recommended,
+  { rules: { 'vue/multi-word-component-names': 'off' } },
+)