Transaktionen: Wartezeit 10 s und Zeitlimit 20 s statt Prisma-Standard

Unter paralleler Last scheiterten Tests sporadisch mit „Unable to start a transaction in the given time“.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/server/db.ts

@@ -406,7 +406,7 @@ export function dbForTenant(tenantId: string) {
               args,
               (a) => delegate[operation](a),
             );
-          });
+          }, TX_DEFAULTS);
         },
       },
     },
@@ -415,6 +415,12 @@ export function dbForTenant(tenantId: string) {
 
 export type TenantDb = ReturnType<typeof dbForTenant>;
 
+/**
+ * Interactive transaction limits. Prisma defaults (maxWait 2 s, timeout 5 s) fail under parallel load
+ * (pool exhausted while notifications/mails run inside a transaction) → wider but still bounded.
+ */
+const TX_DEFAULTS = { maxWait: 10_000, timeout: 20_000 } as const;
+
 /**
  * Run `fn` atomically for one tenant. ALWAYS use this (or `inTransaction` in services)
  * instead of `db.$transaction(...)` for multi-step writes — atomic in both modes:
@@ -431,7 +437,7 @@ export async function tenantTransaction<T>(
 ): Promise<T> {
   if (!RLS_ENFORCED) {
     if (isTransactionClient(db)) return fn(db);
-    return db.$transaction((tx) => fn(tx as unknown as TenantDb), options) as Promise<T>;
+    return db.$transaction((tx) => fn(tx as unknown as TenantDb), { ...TX_DEFAULTS, ...options }) as Promise<T>;
   }
   const active = tenantTx.getStore();
   if (active) {
@@ -441,7 +447,7 @@ export async function tenantTransaction<T>(
   return appBase!.$transaction(async (tx) => {
     await tx.$executeRaw`SELECT set_config('app.tenant_id', ${tenantId}, true)`;
     return tenantTx.run({ tenantId, tx }, () => fn(db));
-  }, options);
+  }, { ...TX_DEFAULTS, ...options });
 }
 
 /** Interactive transaction clients have no $transaction method. */