feat: complete Phase 1 infrastructure

- erp-core: error types, shared types, event bus, ErpModule trait
- erp-server: config loading, database/Redis connections, migrations
- erp-server/migration: tenants table with SeaORM
- apps/web: Vite + React 18 + TypeScript + Ant Design 5 + TailwindCSS
- Web frontend: main layout with sidebar, header, routing
- Docker: PostgreSQL 16 + Redis 7 development environment
- All workspace crates compile successfully (cargo check passes)

apps/web/src/App.tsx

@@ -0,0 +1,30 @@
+import { HashRouter, Routes, Route } from 'react-router-dom';
+import { ConfigProvider, theme as antdTheme } from 'antd';
+import zhCN from 'antd/locale/zh_CN';
+import MainLayout from './layouts/MainLayout';
+import { useAppStore } from './stores/app';
+
+function HomePage() {
+  return <div>欢迎来到 ERP 平台</div>;
+}
+
+export default function App() {
+  const { theme: appTheme } = useAppStore();
+
+  return (
+    <ConfigProvider
+      locale={zhCN}
+      theme={{
+        algorithm: appTheme === 'dark' ? antdTheme.darkAlgorithm : antdTheme.defaultAlgorithm,
+      }}
+    >
+      <HashRouter>
+        <MainLayout>
+          <Routes>
+            <Route path="/" element={<HomePage />} />
+          </Routes>
+        </MainLayout>
+      </HashRouter>
+    </ConfigProvider>
+  );
+}