feat(sync-history): 新增同步结果查询(每次自动/手动/立即同步的记录)

后端：
- db.py SCHEMA 新增 sync_history 表(不可变,每次同步尝试一行) + 索引
- garmin.py: _log_sync_history() 在 sync_data 全部出口记录; trigger 区分
  auto(调度器)/manual(同步页开始同步)/quick(设置页立即同步); start_sync
  限流拦截分支同样留档; 写入失败只告警不影响同步
- scheduler.py 自动同步传 trigger="auto"; routes 新增 GET /garmin/sync-history
  按时间倒序返回(默认 50 条,上限 200)

前端：
- api.ts 增加 SyncHistoryItem 类型 + getSyncHistory()
- 新页面 /sync-history/ 同步记录: 卡片列表, 状态(成功/失败/被限流)chip 配色,
  时间本地化(今天/昨天/X月X日), 触发类型标签, 范围与耗时
- 同步页与设置页同步区块均加入口链接

client/src/services/api.ts

@@ -129,6 +129,26 @@ export interface SyncResult {
   lastSyncTime: string;
 }
 
+/** One recorded sync attempt, for the 同步记录 screen. */
+export interface SyncHistoryItem {
+  /** What started the run: the scheduler, the sync page, or 立即同步. */
+  triggerKind: 'auto' | 'manual' | 'quick';
+  status: 'success' | 'error' | 'rate_limited' | 'syncing';
+  days: number;
+  recordsSynced: number;
+  activitiesSynced: number;
+  badgesSynced: number;
+  personalRecordsSynced: number;
+  startedAt: string;
+  finishedAt: string | null;
+  durationSeconds: number;
+  message: string | null;
+}
+
+export interface SyncHistoryResponse {
+  items: SyncHistoryItem[];
+}
+
 export interface Recommendation {
   id: string;
   category: string;
@@ -664,6 +684,14 @@ class ApiClient {
     return data;
   }
 
+  /** Every recorded sync attempt, newest first (auto / manual / 立即同步). */
+  async getSyncHistory(limit = 50) {
+    const { data } = await this.client.get<SyncHistoryResponse>('/garmin/sync-history', {
+      params: { limit },
+    });
+    return data.items;
+  }
+
   // --- health ---
   private range(startDate?: string, endDate?: string) {
     return { params: { startDate, endDate } };