feat(center-nodes): add node heartbeat endpoint

Fabric.Backend.Center/src/entities/guild-node.entity.ts

@@ -1,4 +1,10 @@
-import { Column, CreateDateColumn, Entity, PrimaryGeneratedColumn } from 'typeorm';
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
 
 @Entity('guild_nodes')
 export class GuildNode {
@@ -21,6 +27,12 @@ export class GuildNode {
   })
   status!: 'active' | 'offline' | 'revoked';
 
+  @Column({ type: 'datetime', nullable: true })
+  lastHeartbeatAt!: Date | null;
+
   @CreateDateColumn()
   createdAt!: Date;
+
+  @UpdateDateColumn()
+  updatedAt!: Date;
 }

Fabric.Backend.Center/src/nodes/nodes.controller.ts

@@ -65,6 +65,27 @@ export class NodesController {
     };
   }
 
+  @Post(':nodeId/heartbeat')
+  async heartbeat(@Param('nodeId') nodeId: string) {
+    const node = await this.nodeRepo.findOne({ where: { nodeId } });
+    if (!node) {
+      throw new NotFoundException('node not found');
+    }
+
+    node.lastHeartbeatAt = new Date();
+    if (node.status !== 'revoked') {
+      node.status = 'active';
+    }
+
+    const saved = await this.nodeRepo.save(node);
+    return {
+      status: 'ok',
+      nodeId: saved.nodeId,
+      nodeStatus: saved.status,
+      lastHeartbeatAt: saved.lastHeartbeatAt,
+    };
+  }
+
   @Patch(':nodeId/status')
   async updateStatus(
     @Param('nodeId') nodeId: string,

docs/TODO-backend-center-guild.md

@@ -27,7 +27,7 @@
 - [x] node 唯一性校验（nodeId/endpoint）
 - [x] node 状态模型（active/offline/revoked）
 - [x] `GET /nodes` 列表 + 分页
-- [ ] node 心跳接口（可选）
+- [x] node 心跳接口（可选）
 
 ### 1.3 Center 运维能力
 - [ ] 审计日志（auth/node 关键操作）