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>

app/routes/dashboard.py

@@ -12,7 +12,7 @@ import httpx
 from fastapi import APIRouter, Depends, Request
 from fastapi.responses import HTMLResponse
 
-from .. import views
+from .. import task_store, views
 from ..deps import get_pulp_client, templates
 from ..pulp_client import PulpClient
 
@@ -21,10 +21,11 @@ router = APIRouter()
 
 def _load_repos(pulp: PulpClient) -> dict[str, Any]:
     """저장소 목록을 읽어 표시 모델 + 요약 + (실패 시) 에러 메시지를 만든다."""
+    syncing = task_store.active_count()
     try:
         repos = pulp.list_repos()
     except httpx.HTTPError as exc:
-        return {"repos": [], "summary": views.summarize([]), "error": str(exc)}
+        return {"repos": [], "summary": views.summarize([], syncing), "error": str(exc)}
 
     repo_views: list[dict[str, Any]] = []
     for repo in repos:
@@ -37,7 +38,11 @@ def _load_repos(pulp: PulpClient) -> dict[str, Any]:
                 version = None  # 버전 상세 실패는 치명적이지 않음 — 행은 표시
         repo_views.append(views.build_repo_view(repo, version))
 
-    return {"repos": repo_views, "summary": views.summarize(repo_views), "error": None}
+    return {
+        "repos": repo_views,
+        "summary": views.summarize(repo_views, syncing),
+        "error": None,
+    }
 
 
 @router.get("/", response_class=HTMLResponse)