Add application codebase: PDF annotation for e-Court

Next.js 14 + Drizzle/PostgreSQL + SSE realtime sync — highlight,
freehand, comment, bookmark + ฟีเจอร์ต่อยอด F1–F19 (edit/move, undo/redo,
shapes, redaction, export PDF/CSV, reply, resolve, search, summary,
textbox, stamp, version history)

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

vitest.config.ts

@@ -0,0 +1,16 @@
+import path from "node:path";
+import { defineConfig } from "vitest/config";
+
+// Unit test เฉพาะ pure utils (ไม่มี DOM/DB — ดูรายละเอียดขอบเขตใน tests/utils/)
+// alias "@" ให้ตรงกับ paths ใน tsconfig.json
+export default defineConfig({
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname),
+    },
+  },
+  test: {
+    environment: "node",
+    include: ["tests/**/*.test.ts"],
+  },
+});