feat(api): start GraphileJobWorkerHost for graphile-based job processing

The GraphileJobWorkerHost was never started when using graphile as the
wakeup driver. Added else-if branch to start the worker host with the
job pool, enabling actual job consumption (previously jobs were queued
but never processed).

apps/api/src/app.ts

@@ -55,6 +55,7 @@ import {
   pipedreamConfigFromEnv,
   piSessionsRoot,
   pushTokenPath,
+  GraphileJobWorkerHost,
   reconcileCloudAgents,
   reconcileComputerUpdates,
   removePiUserSessions,
@@ -427,6 +428,12 @@ export async function createApp(
   });
   if (inMemoryJobs) {
     await inMemoryJobs.start(jobHandlers);
+  } else if (jobPool) {
+    const graphileWorkerHost = new GraphileJobWorkerHost(jobPool, {
+      concurrency: 4,
+      pollInterval: 500,
+    });
+    await graphileWorkerHost.start(jobHandlers);
   }
   const reconciler = inMemoryJobs
     ? createJobReconciler({