feat: 完成P6-P8后端能力与P9路由重构（V1-V2,D1,D3,B1-B2,B4,I1-I4,P9A2-P9A3）

server/src/services/notifications/channels.js

@@ -0,0 +1,75 @@
+const { dispatchOutboxEvent } = require("../integrations/dispatcher");
+
+function applyTemplate(template, context) {
+  if (typeof template !== "string") {
+    return "";
+  }
+
+  return template.replace(/\{\{\s*([a-zA-Z0-9_]+)\s*\}\}/g, (_, key) => {
+    const value = context[key];
+    return value == null ? "" : String(value);
+  });
+}
+
+function buildNotificationMessage(channel, payload) {
+  const context = {
+    title: String(payload?.title ?? "系统通知").slice(0, 200),
+    body: String(payload?.body ?? "").slice(0, 2000),
+    targetType: payload?.targetType ?? "",
+    targetId: payload?.targetId ?? "",
+  };
+
+  const template =
+    channel?.template_json && typeof channel.template_json === "object"
+      ? channel.template_json
+      : null;
+
+  const templatedTitle = template?.title ? applyTemplate(template.title, context) : "";
+  const templatedBody = template?.body ? applyTemplate(template.body, context) : "";
+
+  return {
+    title: (templatedTitle || context.title).slice(0, 200),
+    body: (templatedBody || context.body).slice(0, 2000),
+    targetType: context.targetType || null,
+    targetId: context.targetId || null,
+  };
+}
+
+async function sendInstantMessageByChannel({ config, channel, payload }) {
+  if (!config.imNotifierEnabled) {
+    return {
+      ok: false,
+      code: "im_notifier_disabled",
+      message: "IM notifier disabled",
+    };
+  }
+
+  if (!channel?.enabled) {
+    return {
+      ok: false,
+      code: "channel_disabled",
+      message: "notification channel disabled",
+    };
+  }
+
+  const message = buildNotificationMessage(channel, payload);
+  const result = await dispatchOutboxEvent({
+    config,
+    eventType: "notification.im",
+    payload: {
+      channelType: channel.channel_type,
+      channelName: channel.name,
+      message,
+    },
+  });
+
+  return {
+    ok: true,
+    code: result.code,
+    response: result.response,
+  };
+}
+
+module.exports = {
+  sendInstantMessageByChannel,
+};