fix: release() absichern, DATABASE_URL Startup-Check, execute-Test hinzugefügt

src/server/db/tenant.test.ts

@@ -53,13 +53,15 @@ describe('withTenant', () => {
     ).rejects.toThrow('Ungültige tenantId')
   })
 
-  it('gibt dieselbe Client-Instanz an fn weiter (Connection-Isolation)', async () => {
-    let capturedClient: unknown
-    await withTenant('tenant1', async (client) => {
-      capturedClient = client
-    })
-    // Client muss nach withTenant released worden sein
+  it('released PoolClient nach Ausführung', async () => {
+    await withTenant('tenant1', async () => {})
     expect(mockClient.release).toHaveBeenCalledOnce()
-    expect(capturedClient).toBeDefined()
+  })
+
+  it('execute delegiert an den dedizierten PoolClient', async () => {
+    await withTenant('abc123', async (client) => {
+      await client.execute('DELETE FROM sessions WHERE expired = true')
+    })
+    expect(mockClient.query).toHaveBeenCalledWith('DELETE FROM sessions WHERE expired = true')
   })
 })