fix(build-docs): process hanging

apps/build-docs/src/main.ts

@@ -28,4 +28,13 @@ async function main() {
     cpSync(join(context.baseDir, "user-guide/404.html"), join(context.baseDir, "404.html"));
 }
 
-main();
+// Note: forcing process.exit() because importing notes via the core triggers
+// fire-and-forget async work in `notes.ts#downloadImages` (a 5s setTimeout that
+// re-schedules itself via `asyncPostProcessContent`), which keeps the libuv
+// event loop alive forever even after main() completes.
+main()
+    .then(() => process.exit(0))
+    .catch((error) => {
+        console.error("Error building documentation:", error);
+        process.exit(1);
+    });