fix(docker): restore /app/server.js in standalone build (#1064) (#1067)

Set outputFileTracingRoot back to projectRoot. In Docker, the parent
(monorepoRoot) was /, which caused Next.js to emit server.js at
.next/standalone/app/server.js and pull in /usr, /root, /proc paths,
breaking  from /app.

Fixes #1064

Co-authored-by: Muhammad Ridwan Ramadhan <ridwanramadhan8888@gmail.com>

next.config.mjs

@@ -1,8 +1,7 @@
 import { fileURLToPath } from "node:url";
-import { dirname, resolve } from "node:path";
+import { dirname } from "node:path";
 
 const projectRoot = dirname(fileURLToPath(import.meta.url));
-const monorepoRoot = resolve(projectRoot, "..");
 
 /** @type {import('next').NextConfig} */
 const nextConfig = {
@@ -11,9 +10,9 @@ const nextConfig = {
   turbopack: {
     root: projectRoot
   },
-  outputFileTracingRoot: monorepoRoot,
+  outputFileTracingRoot: projectRoot,
   outputFileTracingExcludes: {
-    "*": ["./app/gitbook/**/*", "./gitbook/**/*"]
+    "*": ["./gitbook/**/*"]
   },
   images: {
     unoptimized: true