Fix Turbopack fs.promises stub for local dev (#60595)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: heiskr

next.config.ts

@@ -70,16 +70,16 @@ const config: NextConfig = {
   turbopack: {
     resolveAlias: {
       fs: {
-        browser: './empty.ts', // Point to empty module when fs is requested for browser
+        browser: './stub.ts',
       },
       async_hooks: {
-        browser: './empty.ts', // Point to empty module when async_hooks is requested for browser
+        browser: './stub.ts',
       },
       '@/observability/logger': {
-        browser: './empty.ts',
+        browser: './stub.ts',
       },
       '@/observability/logger/lib/logger-context': {
-        browser: './empty.ts',
+        browser: './stub.ts',
       },
       '@/observability/lib/tracing': {
         browser: './src/observability/lib/tracing.browser.ts',

empty.ts stub.tsempty.ts renamed to stub.ts

@@ -1,4 +1,4 @@
-// Empty module to satisfy Turbopack resolveAlias fallback for Node.js modules
+// Stub module to satisfy Turbopack resolveAlias fallback for Node.js modules
 // See turbopack config in next.config.ts
 
 // No-op function that returns itself for chaining
@@ -9,4 +9,7 @@ export const createLogger = () => ({
   debug: () => {},
 })
 
+// Stub for fs.promises (used by server-only code that Turbopack traces into client bundles)
+export const promises = {}
+
 export default {}