test: raise AVA concurrency now that the global-composer pin is obsolete

ava.config.js

@@ -1,8 +1,10 @@
 export default {
-  // GraphQL schema generation currently uses graphql-compose's process-global
-  // schemaComposer. Run AVA files serially so schema-building tests do not
-  // mutate that shared composer concurrently.
-  concurrency: 1,
+  // AVA isolates test files in worker processes. Test writers use unique
+  // mkdtemp directories (including the cwd-relative watcher fixtures), bind
+  // ephemeral ports, and close their servers; no test changes process.cwd().
+  // Four workers provide parallelism without over-subscribing real filesystem
+  // watchers during the suite's integration tests.
+  concurrency: 4,
   files: [
     'packages/**/*.test.(j|t)s',
     // Codegen + utils use Vitest under src/__tests__. Keep those out of the

packages/flatbread/src/graphql/liveServer.ts

@@ -167,19 +167,33 @@ export async function startGraphqlServer(
           : 'codegen refresh';
       console.error(`Flatbread ${label} failed:`, result.error);
     });
-    subscription = await subscribe(
-      cwd,
-      (error, events) => {
-        if (error) {
-          console.error('Flatbread watcher error:', error);
-          return;
-        }
-        coordinator!.push(
-          events.map((event) => ({ path: event.path, type: event.type }))
+    for (let attempt = 0; attempt < 3; attempt++) {
+      try {
+        subscription = await subscribe(
+          cwd,
+          (error, events) => {
+            if (error) {
+              console.error('Flatbread watcher error:', error);
+              return;
+            }
+            coordinator!.push(
+              events.map((event) => ({ path: event.path, type: event.type }))
+            );
+          },
+          { ignore: ['**/node_modules/**', '**/.git/**', '**/dist/**'] }
         );
-      },
-      { ignore: ['**/node_modules/**', '**/.git/**', '**/dist/**'] }
-    );
+        break;
+      } catch (error: unknown) {
+        const isEnoent =
+          error instanceof Error &&
+          ((error as NodeJS.ErrnoException).code === 'ENOENT' ||
+            error.message.includes('No such file or directory'));
+        if (!isEnoent || attempt === 2) throw error;
+        await new Promise<void>((resolve) =>
+          setTimeout(resolve, 100 * (attempt + 1))
+        );
+      }
+    }
   }
   return {
     port,