feat(server): 完成 F15 邮件通知（SMTP/Nodemailer）\n\n- 新增 email 服务（EMAIL_ENABLED + SMTP_* 配置）\n- 待办/审批/付款/密码重置触发可选邮件，失败降级不阻塞\n- 更新 server/README 邮件配置说明，并推进 CSV 状态为 DONE

server/src/services/email/index.js

@@ -0,0 +1,165 @@
+const nodemailer = require("nodemailer");
+
+function resolveEmailBaseUrl(config) {
+  const explicit = String(config.emailBaseUrl ?? "").trim();
+  if (explicit) {
+    return explicit.replace(/\/+$/, "");
+  }
+
+  const origin = String(config.appOrigin ?? "").split(",")[0]?.trim?.() ?? "";
+  if (origin) {
+    return origin.replace(/\/+$/, "");
+  }
+
+  return "";
+}
+
+let cachedTransportKey = null;
+let cachedTransporter = null;
+
+function getTransporter(config) {
+  if (!config.emailEnabled) {
+    return null;
+  }
+
+  if (!config.smtpHost) {
+    return null;
+  }
+
+  const authUser = String(config.smtpUser ?? "").trim();
+  const authPass = String(config.smtpPass ?? "").trim();
+
+  const key = JSON.stringify({
+    host: config.smtpHost,
+    port: config.smtpPort,
+    secure: config.smtpSecure,
+    user: authUser,
+  });
+
+  if (cachedTransporter && cachedTransportKey === key) {
+    return cachedTransporter;
+  }
+
+  cachedTransportKey = key;
+  cachedTransporter = nodemailer.createTransport({
+    host: config.smtpHost,
+    port: config.smtpPort,
+    secure: config.smtpSecure,
+    auth: authUser ? { user: authUser, pass: authPass } : undefined,
+  });
+
+  return cachedTransporter;
+}
+
+async function sendNotificationEmailSafe(params) {
+  try {
+    return await sendNotificationEmail(params);
+  } catch (error) {
+    params.logger?.error?.(
+      {
+        err: error,
+        requestId: params.requestId,
+        notificationType: params.type,
+        recipients: params.recipientEmployeeIds?.length ?? 0,
+      },
+      "Failed to send notification email",
+    );
+    return { skipped: false, sent: 0, failed: params.recipientEmployeeIds?.length ?? 0 };
+  }
+}
+
+async function sendNotificationEmail({
+  prisma,
+  config,
+  logger,
+  requestId,
+  recipientEmployeeIds,
+  subject,
+  body,
+  type = "notification",
+  targetPath,
+}) {
+  if (!config.emailEnabled) {
+    return { skipped: true, sent: 0, failed: 0 };
+  }
+
+  const transporter = getTransporter(config);
+  if (!transporter) {
+    logger?.warn?.({ requestId }, "Email enabled but transporter not configured");
+    return { skipped: true, sent: 0, failed: 0 };
+  }
+
+  const recipients = Array.from(new Set((recipientEmployeeIds ?? []).filter(Boolean)));
+  if (!recipients.length) {
+    return { skipped: true, sent: 0, failed: 0 };
+  }
+
+  const employees = await prisma.employee.findMany({
+    where: {
+      id: { in: recipients },
+      status: "active",
+    },
+    select: {
+      id: true,
+      email: true,
+      name: true,
+    },
+  });
+
+  const emailFrom = String(config.emailFrom ?? "").trim();
+  if (!emailFrom) {
+    logger?.warn?.({ requestId }, "Email enabled but EMAIL_FROM is empty");
+    return { skipped: true, sent: 0, failed: 0 };
+  }
+
+  const baseUrl = resolveEmailBaseUrl(config);
+  const link = targetPath && baseUrl ? `${baseUrl}${targetPath}` : null;
+  const safeSubject = String(subject ?? "").trim().slice(0, 200) || "系统通知";
+  const safeBody = String(body ?? "").trim();
+
+  let sent = 0;
+  let failed = 0;
+
+  for (const employee of employees) {
+    if (!employee.email) {
+      failed += 1;
+      continue;
+    }
+
+    const text = link ? `${safeBody}\n\n查看详情：${link}` : safeBody;
+
+    try {
+      await transporter.sendMail({
+        from: emailFrom,
+        to: employee.email,
+        subject: safeSubject,
+        text,
+        headers: {
+          "x-hyb-notification-type": type,
+          "x-request-id": requestId ?? "",
+        },
+      });
+      sent += 1;
+    } catch (error) {
+      failed += 1;
+      logger?.error?.(
+        {
+          err: error,
+          requestId,
+          employeeId: employee.id,
+          email: employee.email,
+          notificationType: type,
+        },
+        "Email send failed",
+      );
+    }
+  }
+
+  return { skipped: false, sent, failed };
+}
+
+module.exports = {
+  sendNotificationEmailSafe,
+  sendNotificationEmail,
+};
+