test: add E2E test for duplicate send access request (#866)

* test: add E2E test for duplicate send access request

Add send-access.spec.ts verifying:
- First request succeeds and balance matches DEFAULT_SEND_BALANCE
- Duplicate request returns 400 (UNIQUE constraint)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* test: assert response body contains 'Already' for duplicate send access

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

e2e/tests/api/send-access.spec.ts

@@ -0,0 +1,31 @@
+import { test, expect } from '@playwright/test';
+import { WORKER_URL, createTestAddress, requestSendAccess, deleteAddress } from '../../fixtures/test-helpers';
+
+test.describe('Send Access', () => {
+  test('request send access succeeds once, duplicate returns 400', async ({ request }) => {
+    const { jwt } = await createTestAddress(request, 'send-access');
+
+    try {
+      // First request — should succeed
+      await requestSendAccess(request, jwt);
+
+      // Verify balance is set via settings
+      const settingsRes = await request.get(`${WORKER_URL}/api/settings`, {
+        headers: { Authorization: `Bearer ${jwt}` },
+      });
+      expect(settingsRes.ok()).toBe(true);
+      const settings = await settingsRes.json();
+      expect(settings.send_balance).toBe(10);
+
+      // Duplicate request — should fail with 400
+      const dupRes = await request.post(`${WORKER_URL}/api/requset_send_mail_access`, {
+        headers: { Authorization: `Bearer ${jwt}` },
+      });
+      expect(dupRes.status()).toBe(400);
+      const dupBody = await dupRes.text();
+      expect(dupBody).toContain('Already');
+    } finally {
+      await deleteAddress(request, jwt);
+    }
+  });
+});