refactor(email): route Resend transport through @bitbaum/mail-kit

package.json

@@ -102,6 +102,8 @@
   "dependencies": {
     "@auth/pg-adapter": "^1.11.3",
     "@aws-sdk/client-s3": "^3.1123.0",
+    "@bitbaum/ai-kit": "^0.6.2",
+    "@bitbaum/mail-kit": "^0.1.0",
     "@fleet/ai-forms": "github:bitbaum/ai-forms#v0.1.2",
     "@sentry/nextjs": "^10.73.0",
     "@tiptap/core": "^3.30.6",
@@ -110,7 +112,6 @@
     "@tiptap/pm": "^3.30.6",
     "@tiptap/react": "^3.30.6",
     "@tiptap/starter-kit": "^3.30.6",
-    "@bitbaum/ai-kit": "^0.6.2",
     "bcryptjs": "^2.4.3",
     "busboy": "^1.6.0",
     "clsx": "^2.1.1",

pnpm-workspace.yaml

@@ -14,6 +14,7 @@ allowBuilds:
   unrs-resolver: true
 minimumReleaseAgeExclude:
   - '@bitbaum/ai-kit'
+  - '@bitbaum/mail-kit'
 overrides:
   '@swc/helpers': 0.5.23
   '@opentelemetry/core': ^2.8.0

src/lib/email/resend.ts

@@ -1,71 +1,52 @@
 /**
- * Resend API client
+ * Resend transport — thin adapter over @bitbaum/mail-kit.
  *
- * The fleet's standard transactional-email provider (see RESEND_API_KEY shared
- * across bitbaum apps). Deliberately a plain fetch to Resend's HTTP API rather
- * than the `resend` SDK: we need exactly one endpoint (POST /emails) and no
- * attachments, so a dependency buys nothing here.
+ * The fleet's one email layer (shared RESEND_API_KEY across bitbaum apps).
+ * mail-kit owns the HTTP call, timeout, and the "configured-looking but dead"
+ * guards (placeholder key, sandbox sender); this file only adapts its
+ * SendResult to evig's SendEmailResult and preserves the throw-on-failure
+ * contract that sendEmail() uses to fall back to SMTP.
  *
  * Sender: only `fleetcrown.orangecat.ch` is verified in the Resend account, so
  * like surf-your-life and vitareba we send as <app>@fleetcrown.orangecat.ch
- * until evig gets its own verified domain.
+ * until evig gets its own verified domain (RESEND_CONFIG.FROM reads
+ * RESEND_FROM with that convention as the default).
  */
 
+import { sendMail, mailHealth, isMailConfigured } from '@bitbaum/mail-kit';
 import { RESEND_CONFIG } from '@/config/email';
 import { logger } from '@/lib/logger';
 import type { EmailContent, SendEmailResult, TestEmailResult } from './types';
 
-const RESEND_API_URL = 'https://api.resend.com';
-
 export function isResendEnabled(): boolean {
-  return Boolean(RESEND_CONFIG.API_KEY);
+  return isMailConfigured();
 }
 
 export async function sendViaResend(to: string, content: EmailContent): Promise<SendEmailResult> {
-  const res = await fetch(`${RESEND_API_URL}/emails`, {
-    method: 'POST',
-    headers: {
-      Authorization: `Bearer ${RESEND_CONFIG.API_KEY}`,
-      'Content-Type': 'application/json',
-    },
-    body: JSON.stringify({
-      from: RESEND_CONFIG.FROM,
-      to: [to],
-      subject: content.subject,
-      html: content.html,
-      text: content.text,
-    }),
+  const result = await sendMail({
+    to,
+    from: RESEND_CONFIG.FROM,
+    subject: content.subject,
+    html: content.html,
+    text: content.text,
   });
 
-  if (!res.ok) {
-    const detail = await res.text().catch(() => '');
+  if (!result.sent) {
     // Throw instead of returning failure: sendEmail() treats a thrown resend
     // error as "fall back to SMTP", mirroring the existing Listmonk pattern.
-    throw new Error(`Resend send failed (${res.status}): ${detail.slice(0, 200)}`);
+    throw new Error(`Resend send failed: ${result.error}`);
   }
 
-  const body = (await res.json()) as { id?: string };
-  logger.info('Email sent via Resend', { messageId: body.id, to });
-  return { success: true, messageId: body.id };
+  logger.info('Email sent via Resend', { messageId: result.id, to });
+  return { success: true, messageId: result.id };
 }
 
 /**
- * Connection test for the diagnostics endpoint: an authenticated read against
- * /domains proves key validity without sending anything.
+ * Connection test for the diagnostics endpoint: mail-kit's health probe does
+ * an authenticated read against /domains — proves key validity without
+ * sending anything.
  */
 export async function testResendConnection(): Promise<TestEmailResult> {
-  try {
-    const res = await fetch(`${RESEND_API_URL}/domains`, {
-      headers: { Authorization: `Bearer ${RESEND_CONFIG.API_KEY}` },
-    });
-    if (!res.ok) {
-      return { success: false, error: `Resend API returned ${res.status}` };
-    }
-    return { success: true };
-  } catch (error) {
-    return {
-      success: false,
-      error: error instanceof Error ? error.message : 'Unknown error',
-    };
-  }
+  const health = await mailHealth();
+  return health.ok ? { success: true } : { success: false, error: health.error };
 }