fix: set the transaction name on the isolation scope level

Author: logaretm

packages/nextjs/src/common/pages-router-instrumentation/wrapApiHandlerWithSentry.ts

@@ -50,12 +50,13 @@ export function wrapApiHandlerWithSentry(apiHandler: NextApiHandler, parameteriz
 
         req.__withSentry_applied__ = true;
 
-        // Set transaction name even without tracing to ensure parameterized routes are used
+        // Set transaction name on isolation scope to ensure parameterized routes are used
+        // The HTTP server integration sets it on isolation scope, so we need to match that
         const method = req.method || 'GET';
-        getCurrentScope().setTransactionName(`${method} ${parameterizedRoute}`);
-
+        const isolationScope = getIsolationScope();
+        isolationScope.setTransactionName(`${method} ${parameterizedRoute}`);
         // Set SDK processing metadata
-        getIsolationScope().setSDKProcessingMetadata({
+        isolationScope.setSDKProcessingMetadata({
           normalizedRequest: httpRequestToRequestData(req),
         });