feat: add MailService.cashboxExport and email template

myteamwallet_backend/src/mail/mail.service.spec.ts

@@ -58,4 +58,28 @@ describe('MailService', () => {
     const call = sendMail.mock.calls[0][0];
     expect(call.context.firstName).toBeUndefined();
   });
+
+  it('sends the cashbox export mail with the PDF attachment', async () => {
+    const attachment = Buffer.from('%PDF-1.4 fake');
+
+    await service.cashboxExport(
+      {
+        to: 'vorstand@example.com, kassier@example.com',
+        data: { teamName: 'Team A', from: '2026-08-01', to: '2026-08-31' },
+      },
+      attachment,
+      'kassenbuch_team-a_2026-08-01_2026-08-31.pdf',
+    );
+
+    expect(sendMail).toHaveBeenCalledTimes(1);
+    const call = sendMail.mock.calls[0][0];
+    expect(call.to).toBe('vorstand@example.com, kassier@example.com');
+    expect(call.template).toBe('cashbox-export');
+    expect(call.context.teamName).toBe('Team A');
+    expect(call.context.from).toBe('2026-08-01');
+    expect(call.context.to).toBe('2026-08-31');
+    expect(call.attachments).toEqual([
+      { filename: 'kassenbuch_team-a_2026-08-01_2026-08-31.pdf', content: attachment },
+    ]);
+  });
 });