feat(M1): Project scaffolding, DB schema, core infrastructure

- Initialize Rust workspace with 7 crates (pm-web, pm-worker, pm-core,
  pm-agent-client, pm-auth, pm-ca, pm-reports)
- React + TypeScript + Vite + MUI frontend scaffold
- Full PostgreSQL schema: all 17 tables with indexes and constraints
- pm-core: config (TOML+env), db (SQLx pool + migrations), error
  (unified AppError + JSON envelope), request_id (ULID middleware),
  logging (tracing JSON/pretty)
- pm-web: Axum skeleton, /status/health endpoint, static file serving
- pm-worker: Tokio skeleton, heartbeat writer, schema version check
- Embedded sqlx migrations with advisory lock (single-writer)
- systemd unit files, setup.sh, build-frontend.sh
- config.example.toml with all configuration keys
- docs/runbooks/restore.md
- cargo check passes with zero warnings

Closes M1.

frontend/vite.config.ts

@@ -0,0 +1,37 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+import { resolve } from 'path'
+
+export default defineConfig({
+  plugins: [react()],
+  resolve: {
+    alias: {
+      '@': resolve(__dirname, './src'),
+    },
+  },
+  server: {
+    port: 3000,
+    proxy: {
+      '/api': {
+        target: 'http://localhost:8080',
+        changeOrigin: true,
+      },
+      '/status': {
+        target: 'http://localhost:8080',
+        changeOrigin: true,
+      },
+    },
+  },
+  build: {
+    outDir: 'dist',
+    sourcemap: false,
+    rollupOptions: {
+      output: {
+        manualChunks: {
+          vendor: ['react', 'react-dom', 'react-router-dom'],
+          mui: ['@mui/material', '@mui/icons-material'],
+        },
+      },
+    },
+  },
+})