fix(#265 review): CRS 3857→4326 + stable zone_id hash + rename 102 + tx comment

- #1 (BLOCK): ST_GeogFromGeoJSON → ST_Transform(ST_SetSRID(..., 3857), 4326)::geography
  so EPSG:3857 features from get_territorial_zones_in_bbox are correctly
  stored in GEOGRAPHY(POLYGON, 4326) column (matches cad_parcels/cad_buildings pattern)
- #2: zone_id fallback changed from counter-based f"{quarter_cad}_{inserted}"
  to md5(json(props))[:12] — stable between runs, prevents wrong-row ON CONFLICT
- #3: rename 101_cad_nspd_overlay_tables.sql → 102_* (101_user_custom_pois.sql exists)
- #4: add comment clarifying SQLAlchemy autobegin guarantees outer tx before begin_nested()
- Tests: updated test_feature_without_zone_id_uses_fallback to assert md5 format + idempotency

backend/app/services/cadastre/bulk_harvest.py

@@ -19,6 +19,7 @@ Resumable: phase_state в cadastre_jobs показывает прогресс.
 
 from __future__ import annotations
 
+import hashlib
 import json
 import logging
 from collections.abc import Callable
@@ -1210,10 +1211,16 @@ def _save_territorial_zones(db: Session, quarter_cad: str, features: list[dict])
         geom = f.get("geometry")
         geom_geojson: str | None = json.dumps(geom) if geom else None
 
-        # zone_id — NSPD feature id или синтетический fallback
-        zone_id = str(
-            props.get("id") or props.get("zone_id") or f.get("id") or f"{quarter_cad}_{inserted}"
-        )
+        # zone_id — NSPD feature id или стабильный fallback на основе md5 от properties.
+        # md5 гарантирует идемпотентность между runs (счётчик inserted сбрасывается).
+        _raw_id = props.get("id") or props.get("zone_id") or f.get("id")
+        if _raw_id:
+            zone_id = str(_raw_id)
+        else:
+            _props_hash = hashlib.md5(
+                json.dumps(props, sort_keys=True).encode("utf-8")
+            ).hexdigest()[:12]
+            zone_id = f"{quarter_cad}_{_props_hash}"
         zone_code = (
             props.get("zone_code") or props.get("zone_index") or props.get("reg_numb_border")
         )
@@ -1221,6 +1228,9 @@ def _save_territorial_zones(db: Session, quarter_cad: str, features: list[dict])
         permitted_use = props.get("permitted_use") or props.get("vri")
 
         try:
+            # begin_nested() требует активной outer-транзакции для SAVEPOINT.
+            # SQLAlchemy Session (autobegin=True) автоматически начинает tx при первом
+            # db.execute() в этом loop — outer tx гарантирована.
             with db.begin_nested():
                 db.execute(
                     text("""
@@ -1235,7 +1245,10 @@ def _save_territorial_zones(db: Session, quarter_cad: str, features: list[dict])
                             CAST(:permitted_use AS text),
                             CAST(:raw_props AS jsonb),
                             CASE WHEN CAST(:geom AS text) IS NOT NULL
-                                THEN ST_GeogFromGeoJSON(CAST(:geom AS text))
+                                THEN ST_Transform(
+                                    ST_SetSRID(ST_GeomFromGeoJSON(CAST(:geom AS text)), 3857),
+                                    4326
+                                )::geography
                                 ELSE NULL
                             END
                         )

backend/tests/services/cadastre/test_bulk_harvest_territorial.py

@@ -102,7 +102,7 @@ class TestSaveTerritorialZones:
         assert call_kwargs["geom"] is None
 
     def test_feature_without_zone_id_uses_fallback(self) -> None:
-        """Feature без id → синтетический fallback zone_id не вызывает краш."""
+        """Feature без id → md5-based fallback zone_id (stable между runs)."""
         db = _make_db_mock()
         features = [
             {
@@ -116,8 +116,18 @@ class TestSaveTerritorialZones:
 
         assert result == 1
         call_kwargs = db.execute.call_args[0][1]
-        # fallback zone_id содержит quarter_cad
-        assert "66:41:0204016" in call_kwargs["zone_id"]
+        zone_id: str = call_kwargs["zone_id"]
+        # fallback zone_id содержит quarter_cad и стабильный hash (12 hex chars)
+        assert zone_id.startswith("66:41:0204016_")
+        suffix = zone_id.split("_", 3)[-1]
+        assert len(suffix) == 12
+        assert all(c in "0123456789abcdef" for c in suffix)
+
+        # Второй вызов с теми же данными → тот же zone_id (идемпотентность)
+        db2 = _make_db_mock()
+        _save_territorial_zones(db2, "66:41:0204016", features)
+        call_kwargs2 = db2.execute.call_args[0][1]
+        assert call_kwargs2["zone_id"] == zone_id
 
     def test_zone_id_from_props_id(self) -> None:
         """Если feature.id=None, но props['id'] есть — используется props['id']."""