fix(tradein): yandex sweep — guard ext_id=NULL перед fetch_jk + cleanup httpx (#974 review M1/M3)

M1: добавлен guard перед вызовом fetch_jk — если ext_id пустой/None при наличии
jk_slug, логируем warning, incrementим failed_fetch и пропускаем (continue).
Пустой jk_id формирует битый URL /{slug}-/ и коллизию на UNIQUE ext_id=''.

M3: в admin.py /scrape/yandex-newbuilding заменён `async with YandexNewbuildingScraper()`
на прямое `scraper = YandexNewbuildingScraper()` — fetch_jk использует внутренний
BrowserFetcher, httpx-клиент BaseScraper открывался вхолостую.

Тесты: добавлен test_sweep_slug_present_but_ext_id_null_skips_fetch.

tradein-mvp/backend/app/api/v1/admin.py

@@ -1468,8 +1468,9 @@ async def scrape_yandex_newbuilding(
 
     URL: /{city}/kupit/novostrojka/<slug>-<id>/
     """
-    async with YandexNewbuildingScraper() as scraper:
-        result = await scraper.fetch_jk(jk_slug=slug, jk_id=id, city=city)
+    # fetch_jk использует внутренний BrowserFetcher, httpx-клиент BaseScraper не нужен
+    scraper = YandexNewbuildingScraper()
+    result = await scraper.fetch_jk(jk_slug=slug, jk_id=id, city=city)
     if result is None:
         raise HTTPException(404, f"Could not parse Yandex JK: {slug}-{id} in {city}")
     return YandexNewbuildingTriggerResp(

tradein-mvp/backend/app/tasks/yandex_newbuilding_sweep.py

@@ -312,11 +312,22 @@ async def enrich_yandex_newbuilding_sweep(
             jk_slug = resolved
             result.resolved_slug += 1
 
+        # ── Guard: ext_id обязателен для fetch_jk (формирует URL /{slug}-{id}/) ──
+        if not ext_id:
+            logger.warning(
+                "house_id=%s: jk_slug=%s известен, но ext_id пустой — "
+                "fetch_jk пропущен (пустой jk_id даёт битый URL)",
+                house_id,
+                jk_slug,
+            )
+            result.failed_fetch += 1
+            continue
+
         # ── Fetch через BrowserFetcher ────────────────────────────────────
         info = None
         try:
             scraper = YandexNewbuildingScraper()
-            info = await scraper.fetch_jk(jk_slug=jk_slug, jk_id=ext_id or "", city=city)
+            info = await scraper.fetch_jk(jk_slug=jk_slug, jk_id=ext_id, city=city)
         except Exception as exc:
             logger.warning(
                 "fetch_jk failed house_id=%s jk_slug=%s ext_id=%s: %s",

tradein-mvp/backend/tests/tasks/test_yandex_newbuilding_sweep.py

@@ -364,3 +364,34 @@ async def test_sweep_no_ext_id_fails_resolve():
 
     assert result.failed_resolve == 1
     assert result.succeeded == 0
+
+
+@pytest.mark.asyncio
+async def test_sweep_slug_present_but_ext_id_null_skips_fetch():
+    """House с jk_slug но ext_id=NULL → guard срабатывает, fetch_jk НЕ вызван.
+
+    M1 review: пустой jk_id даёт URL /{slug}-/, который является битым.
+    Ожидаем failed_fetch += 1 и scraper.fetch_jk не вызван.
+    """
+    db = FakeDB(
+        [
+            {
+                "house_id": 70,
+                "ext_id": None,
+                "yandex_jk_slug": "tatlin",
+                "yandex_jk_id": None,
+            }
+        ]
+    )
+
+    with patch("app.services.scrapers.yandex_newbuilding.YandexNewbuildingScraper") as mock_scraper:
+        scraper_instance = MagicMock()
+        scraper_instance.fetch_jk = AsyncMock()
+        mock_scraper.return_value = scraper_instance
+
+        result = await enrich_yandex_newbuilding_sweep(db, limit=5, request_delay_sec=0)
+
+    scraper_instance.fetch_jk.assert_not_called()
+    assert result.failed_fetch == 1
+    assert result.succeeded == 0
+    assert result.rows_inserted == 0