feat: FastAPI console with dashboard, Pulp client, healthz (stages 0-1)

- config: PULP_* env + 사내 CA(verify=) 대응
- pulp_client: Basic Auth get/post/patch, status/list_repos/get_version
- BFF 라우트: GET / (대시보드), GET /repos (조각), GET /healthz
- views: Pulp JSON → 표시 모델 (GPG 검증 배지 3단계, 요약 집계)
- HTMX + Jinja 템플릿, vendored pico.css/htmx.js (CDN 의존 0)
- 브라우저는 Pulp 직접 호출 안 함 — 모두 BFF 경유 (스펙 §2)
- 테스트: pulp_client(respx), 라우트(dependency_overrides), views 순수함수

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

tests/test_healthz.py

@@ -0,0 +1,36 @@
+import httpx
+from fastapi.testclient import TestClient
+
+from app.main import app, get_pulp_client
+
+client = TestClient(app)
+
+
+class _FakeOnline:
+    def status(self):
+        return {"online": True}
+
+
+class _FakeDown:
+    def status(self):
+        raise httpx.ConnectError("connection refused")
+
+
+def test_healthz_online():
+    app.dependency_overrides[get_pulp_client] = lambda: _FakeOnline()
+    try:
+        resp = client.get("/healthz")
+    finally:
+        app.dependency_overrides.clear()
+    assert resp.status_code == 200
+    assert "연결됨" in resp.text
+
+
+def test_healthz_offline_when_pulp_down():
+    app.dependency_overrides[get_pulp_client] = lambda: _FakeDown()
+    try:
+        resp = client.get("/healthz")
+    finally:
+        app.dependency_overrides.clear()
+    assert resp.status_code == 503
+    assert "연결 실패" in resp.text