test: Backend-e2e in CI stabil (eigene Jahre, Sperren, ein Server je App)

- daily-evaluation nutzt die Jahre 2011/2012 statt 2001, damit der Job nicht
  die Daten von autopilot und reminders liest und verändert.
- throttler: app.listen(0) einmal je App statt eines Servers je Anfrage
  (ECONNRESET bei 40 parallelen Anfragen).
- outbox-claims: 120 s Zeitlimit für 2000 sequentielle Anweisungen.
- migration-harness: eine `migrate deploy` zur Zeit über eine eigene
  Advisory-Sperre (P1002 bei parallelen Migrations-Suites).
- authority-notices und authority-notices-herd laufen über
  exclusive-suite nacheinander; Herd-Wiederholung räumt eigene Entwürfe.

Refs #32

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Backend/test/utils/exclusive-suite.ts

@@ -0,0 +1,31 @@
+import { Client } from 'pg';
+
+/** Arbitrary keys, one per shared resource a suite needs to own alone. */
+export const EXCLUSIVE_KEYS = {
+  /** Open drafts are unique per kind: only one suite may create/clear them. */
+  authorityNotices: 72707371,
+} as const;
+
+/**
+ * Holds a Postgres session advisory lock for the lifetime of a suite, so
+ * suites that clear or count a table whose rows are global (e.g. the open
+ * draft per notice kind) never run at the same time, even in parallel jest
+ * workers. Blocks until the previous owner released it; the lock disappears
+ * with the connection if a worker dies. Call release() in afterAll.
+ */
+export async function acquireExclusive(
+  key: number,
+): Promise<() => Promise<void>> {
+  const url = process.env.DATABASE_URL;
+  if (!url) {
+    throw new Error('DATABASE_URL is not set');
+  }
+  const connection = new URL(url);
+  connection.searchParams.delete('schema');
+  const client = new Client({ connectionString: connection.toString() });
+  await client.connect();
+  await client.query('SELECT pg_advisory_lock($1)', [key]);
+  return async () => {
+    await client.end();
+  };
+}