feat(web): 强制同步按钮（列表+详情）；test: 强制同步语义断言（force 立即执行并刷新 next_sync_at）

internal/creator/integration_test.go

@@ -304,6 +304,22 @@ func TestCreatorPostgresContentAndWorkflow(t *testing.T) {
 	if due, err := store.ListDueCompetitors(ctx, dueNow); err != nil || len(due) != 0 {
 		t.Fatalf("blocked competitor must not fire before retry time: due=%+v err=%v", due, err)
 	}
+	// 强制同步语义：next_sync_at 未到期时 force claim 仍立即执行；完成后 MarkCompetitorSync 刷新 next_sync_at。
+	if _, claimed, err := store.ClaimCompetitorSync(ctx, competitor.ID, false, dueNow); err != nil || claimed {
+		t.Fatalf("non-forced claim must wait for next_sync_at: claimed=%v err=%v", claimed, err)
+	}
+	forceToken, forceClaimed, err := store.ClaimCompetitorSync(ctx, competitor.ID, true, dueNow)
+	if err != nil || !forceClaimed {
+		t.Fatalf("forced claim must run before next_sync_at: err=%v claimed=%v", err, forceClaimed)
+	}
+	forceNext := dueNow.Add(30 * time.Minute)
+	if err := store.MarkCompetitorSync(ctx, competitor.ID, forceToken, "idle", "", "", &forceNext); err != nil {
+		t.Fatal(err)
+	}
+	// Postgres timestamp 微秒精度会截断纳秒，比较用秒级容差。
+	if refreshed, err := store.GetCompetitor(ctx, competitor.ID); err != nil || refreshed.NextSyncAt == nil || refreshed.NextSyncAt.Sub(forceNext).Abs() > time.Second {
+		t.Fatalf("forced sync must refresh next_sync_at: next=%v err=%v", refreshed.NextSyncAt, err)
+	}
 	work, inserted, err = store.UpsertWork(ctx, WorkInput{Platform: PlatformDouyin, WorkKey: workKey, SourceType: SourceCompetitor, SourceID: competitor.ID, Title: "", Body: "", PublishedAt: nil, Likes: nil, CommentsCount: nil, Shares: nil}, now)
 	if err != nil || inserted || len(work.Sources) != 2 {
 		t.Fatalf("work source association was not retained: work=%+v inserted=%v err=%v", work, inserted, err)

web/src/components/accounts/MonitoringAccountList.tsx

@@ -198,7 +198,7 @@ export default function MonitoringAccountList() {
                     编辑标签
                   </Button>
                   <Button size="small" disabled={actionBusy === row.id} onClick={() => syncCompetitor(row)}>
-                    同步
+                    强制同步
                   </Button>
                   <Button size="small" disabled={actionBusy === row.id} onClick={() => toggleCompetitor(row)}>
                     {row.enabled ? '暂停' : '恢复'}

web/src/pages/accounts/monitoring/$id/index.tsx

@@ -149,7 +149,7 @@ export default function Page() {
             }
           }}
         >
-          立即同步
+          强制同步
         </Button>
         <Button
           type="primary"