feat: sync execution with 3s progress polling (stage 2)

- pulp_client: get_repo / sync_repo / get_task (비동기 task href 반환)
- POST /repos/{uuid}/sync: remote 확인 후 동기화 시작, 진행률 조각 반환
- GET /repos/{uuid}/progress: progress_reports 합산 → 바/퍼센트,
  완료/실패 시 hx-trigger 제거로 폴링 중단
- task_store: uuid→task_href 메모리 추적 (단일 인스턴스), 대시보드 '동기화 중' 집계
- views.task_progress: state/done/total/percent + created_resources에서 새 vN
- 동기화는 안전 동작이라 확인 모달 없이 실행 (스펙 §5-1)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_views.py

@@ -70,3 +70,34 @@ def test_summarize_counts():
         "gpg_pass": 2,
         "total_packages": 150,
     }
+
+
+def test_summarize_includes_syncing_count():
+    assert views.summarize([], syncing=2)["syncing"] == 2
+
+
+def test_task_progress_running_sums_reports():
+    task = {
+        "state": "running",
+        "progress_reports": [{"done": 5, "total": 10}, {"done": 3, "total": 10}],
+    }
+    p = views.task_progress(task)
+    assert p["running"] is True
+    assert p["completed"] is False
+    assert (p["done"], p["total"], p["percent"]) == (8, 20, 40)
+
+
+def test_task_progress_completed_extracts_version():
+    task = {
+        "state": "completed",
+        "created_resources": ["/pulp/api/v3/repositories/rpm/rpm/x/versions/4/"],
+    }
+    p = views.task_progress(task)
+    assert p["completed"] is True
+    assert p["new_version"] == 4
+
+
+def test_task_progress_failed_surfaces_error():
+    p = views.task_progress({"state": "failed", "error": {"description": "boom"}})
+    assert p["failed"] is True
+    assert p["error"] == "boom"