feat(sync): implement sync stubs with env-var gating and status endpoint

apps/server/src/sync/sync.service.ts

@@ -91,6 +91,13 @@ export class SyncService {
     return this.syncLogRepo.find({ where, order: { createdAt: 'DESC' }, take: limit });
   }
 
+  async getLastSync(platform: SyncPlatform): Promise<SyncLog | null> {
+    return this.syncLogRepo.findOne({
+      where: { platform },
+      order: { createdAt: 'DESC' },
+    });
+  }
+
   // ── Private helpers ──
 
   private async determineSyncType(platform: SyncPlatform): Promise<SyncType> {
@@ -145,20 +152,28 @@ export class SyncService {
    * Pass `lastSyncAt` to the DingTalk API for incremental sync.
    */
   private async performDingTalkSync(_lastSyncAt: Date | null): Promise<number> {
-    // TODO: Call DingTalk API — e.g. attendance records, user list, etc.
-    // const records = await this.dingTalkClient.fetchAttendance({ updatedAfter: lastSyncAt });
-    // return records.length;
+    const appKey = process.env.DINGTALK_APP_KEY;
+    if (!appKey) {
+      this.logger.warn('DingTalk not configured (DINGTALK_APP_KEY missing), skipping sync');
+      return 0;
+    }
+
+    this.logger.warn(
+      'DingTalk integration service not yet implemented — add DingTalkService to SyncModule to enable real sync',
+    );
     return 0;
   }
 
-  /**
-   * Perform the actual WeCom data pull.
-   * Pass `lastSyncAt` to the WeCom API for incremental sync.
-   */
   private async performWeComSync(_lastSyncAt: Date | null): Promise<number> {
-    // TODO: Call WeCom API — e.g. contacts, attendance, etc.
-    // const records = await this.weComClient.fetchContacts({ updatedAfter: lastSyncAt });
-    // return records.length;
+    const corpId = process.env.WECOM_CORP_ID;
+    if (!corpId) {
+      this.logger.warn('WeCom not configured (WECOM_CORP_ID missing), skipping sync');
+      return 0;
+    }
+
+    this.logger.warn(
+      'WeCom integration service not yet implemented — add WeComService to SyncModule to enable real sync',
+    );
     return 0;
   }
 }