fix(estimator): Yandex history freshness filter в price_trend (#audit-3)

_fetch_price_trend(freshness_months) — новый параметр, дефолт из
settings.estimate_price_trend_max_age_months (6 мес).
WHERE scraped_at > now() - N months исключает устаревшие items
(yandex_valuation 2024 и т.д.) из house_placement_history fallback.
houses_price_dynamics (Source 1) не затронут. psycopg v3 CAST syntax.

tradein-mvp/backend/app/services/estimator.py

@@ -2978,7 +2978,12 @@ async def estimate_quality(
     freshness_min = _compute_freshness_minutes(metadata_lots)
     last_scraped_at = _compute_last_scraped_at(metadata_lots)
     # Месячный ₽/м² тренд целевого дома (web TREND chart) — best-effort, None если нет данных.
-    price_trend_raw = _fetch_price_trend(db, target_house_id=target_house_id)
+    # #audit-3: передаём freshness_months из настроек — исключаем устаревшие items.
+    price_trend_raw = _fetch_price_trend(
+        db,
+        target_house_id=target_house_id,
+        freshness_months=settings.estimate_price_trend_max_age_months,
+    )
     price_trend = (
         [PriceTrendPoint(month=p["month"], ppm2=p["ppm2"]) for p in price_trend_raw]
         if price_trend_raw
@@ -3143,6 +3148,7 @@ def _fetch_price_trend(
     target_house_id: int | None,
     months: int = 24,
     min_points: int = 3,
+    freshness_months: int | None = None,
 ) -> list[dict[str, Any]] | None:
     """Месячный ₽/м² тренд для целевого дома (web TREND chart) — best-effort.
 
@@ -3200,6 +3206,10 @@ def _fetch_price_trend(
         return trend
 
     # ── Source 2 (fallback): aggregate house_placement_history by month ──────
+    # #audit-3: freshness_months — фильтр по scraped_at чтобы исключить стale items
+    # (yandex_valuation из 2024 и т.д.). Применяется ко ВСЕМ source в этом запросе
+    # (avito_imv + yandex_valuation), не только к yandex_valuation. Дефолт из config.
+    _fresh_months = freshness_months if freshness_months is not None else months
     try:
         rows = (
             db.execute(
@@ -3223,11 +3233,14 @@ def _fetch_price_trend(
                       AND COALESCE(last_price_date, start_price_date) IS NOT NULL
                       AND COALESCE(last_price_date, start_price_date) > (CURRENT_DATE
                           - (CAST(:months AS integer) || ' months')::interval)
+                      AND scraped_at > (now()
+                          - CAST(:fresh_months AS integer)
+                          * CAST('1 month' AS interval))
                     GROUP BY 1
                     ORDER BY 1 ASC
                     """
                 ),
-                {"hid": target_house_id, "months": months},
+                {"hid": target_house_id, "months": months, "fresh_months": _fresh_months},
             )
             .mappings()
             .all()