Retry incomplete controller startup (Refs #65)

src/hooks.server.ts

@@ -9,21 +9,24 @@ import { withOperationSource } from '$lib/server/hosts/operation-context.js';
 import { withHostRequestContext } from '$lib/server/hosts/request-context.js';
 
 let booted = false;
+let rejectionLoggerRegistered = false;
 function boot(): void {
     if (booted) return;
-    booted = true;
-    process.on('unhandledRejection', reason => {
-        console.error('[process] unhandled rejection:', reason);
-    });
+    if (!rejectionLoggerRegistered) {
+        process.on('unhandledRejection', reason => {
+            console.error('[process] unhandled rejection:', reason);
+        });
+        rejectionLoggerRegistered = true;
+    }
     migrate();
     interruptDeployments();
     startWorker();
     startPerformanceMonitor();
+    booted = true;
 }
 
-// SvelteKit calls handle() for every request; using the first request as the
-// boot trigger keeps the whole app single-process without needing an
-// out-of-band init hook.
+// Boot synchronously before serving requests. Failed startup stays unbooted so
+// the next request retries migrations and worker startup before reaching the UI.
 export const handle: Handle = async (input) => {
     boot();
     const started = performance.now();