fix(instrumentation): remove process.once Edge warnings

instrumentation.ts

@@ -94,6 +94,7 @@ export async function register(): Promise<void> {
     return shutdownPromise;
   };
 
-  process.once('SIGTERM', () => void shutdown());
-  process.once('SIGINT', () => void shutdown());
+  // Imported dynamically so the Edge bundle never contains `process.once`.
+  const { registerShutdownSignals } = await import('@/lib/server/shutdown-signals');
+  registerShutdownSignals(shutdown);
 }

lib/server/shutdown-signals.ts

@@ -0,0 +1,11 @@
+/**
+ * Node-only shutdown signal wiring.
+ *
+ * Kept out of `instrumentation.ts` so the Edge runtime bundle never contains
+ * `process.once`, which Next's Edge compiler rejects as a Node.js API. The
+ * parent module imports this dynamically and only on the Node.js runtime.
+ */
+export function registerShutdownSignals(shutdown: () => Promise<void>): void {
+  process.once('SIGTERM', () => void shutdown());
+  process.once('SIGINT', () => void shutdown());
+}