fix(nspd): rename migration 89→98, fix red lines ST_Area→ST_Length (#220)

- data/sql/98_*: rename from 89 to avoid collision with existing 89_drop_dead_brin
- _get_red_lines: ST_Length(ST_Intersection(planar)::geography) instead of
  ST_Area(ST_Intersection(::geography, ::geography)) — fixes PostGIS 3.4
  tolerance error and returns correct non-zero length for LINESTRING intersections
- Rename intersection_area_sqm → intersection_length_m across schema, TS types,
  frontend component, and tests; add test_get_red_lines_db_exception_returns_empty

Addresses review-bot feedback on PR #220.

backend/app/schemas/parcel.py

@@ -105,17 +105,18 @@ class RedLine(BaseModel):
 
     Поля:
         geom_wkt: WKT геометрии линии в EPSG:4326
-        intersection_area_sqm: площадь пересечения с участком, м² (null если только nearby)
+        intersection_length_m: длина пересечения линии с участком, м
+                               (null если только nearby, не intersect)
         distance_m: расстояние от ближайшей точки линии до участка, м
                     (null если линия пересекает участок)
 
     UI-семантика:
-        intersection_area_sqm != null → красная линия ПЕРЕСЕКАЕТ участок (ALERT)
+        intersection_length_m != null → красная линия ПЕРЕСЕКАЕТ участок (ALERT)
         distance_m != null → красная линия рядом (warning)
     """
 
     geom_wkt: str | None
-    intersection_area_sqm: float | None  # null если только nearby, не intersect
+    intersection_length_m: float | None  # null если только nearby, не intersect
     distance_m: float | None  # null если intersect
 
 

backend/app/services/site_finder/quarter_dump_lookup.py

@@ -685,11 +685,15 @@ def _get_red_lines(
     """TIER 4: красные линии застройки (layer 879243).
 
     Возвращает red lines пересекающие участок ИЛИ ближайшие (до 200м) с полями:
-        geom_wkt, intersection_area_sqm, distance_m.
+        geom_wkt, intersection_length_m, distance_m.
 
     Логика:
-        - intersecting: intersection_area_sqm > 0, distance_m = None
-        - nearby only: intersection_area_sqm = None, distance_m = расстояние
+        - intersecting: intersection_length_m >= 0, distance_m = None
+        - nearby only: intersection_length_m = None, distance_m = расстояние
+
+    ST_Intersection выполняется в planar EPSG:4326, затем результат кастуется
+    в ::geography для ST_Length — это избегает PostGIS 3.4 tolerance bug
+    (ST_Intersection geography × geography на LINESTRING бросает transform error).
 
     layer_counts — денормализованные счётчики. Если red_lines_count == 0 —
     пропускаем heavy jsonb_array_elements scan.
@@ -719,7 +723,7 @@ def _get_red_lines(
                            ),
                            ST_GeomFromText(:wkt, 4326)
                        )                             AS does_intersect,
-                       ST_Area(
+                       ST_Length(
                            ST_Intersection(
                                ST_Transform(
                                    ST_SetSRID(
@@ -727,10 +731,10 @@ def _get_red_lines(
                                        3857
                                    ),
                                    4326
-                               )::geography,
-                               ST_GeomFromText(:wkt, 4326)::geography
-                           )
-                       )                             AS intersection_area_sqm,
+                               ),
+                               ST_GeomFromText(:wkt, 4326)
+                           )::geography
+                       )                             AS intersection_length_m,
                        ST_Distance(
                            ST_Transform(
                                ST_SetSRID(
@@ -769,14 +773,14 @@ def _get_red_lines(
         for r in rows:
             geom_wkt_val: str | None = r[0]
             does_intersect: bool = bool(r[1]) if r[1] is not None else False
-            raw_area: Any = r[2]
+            raw_length: Any = r[2]
             raw_dist: Any = r[3]
 
-            intersection_area_sqm: float | None = None
-            if does_intersect and raw_area is not None:
+            intersection_length_m: float | None = None
+            if does_intersect and raw_length is not None:
                 try:
-                    val = float(raw_area)
-                    intersection_area_sqm = round(val, 1) if not math.isnan(val) else None
+                    val = float(raw_length)
+                    intersection_length_m = round(val, 1) if not math.isnan(val) else None
                 except (TypeError, ValueError):
                     pass
 
@@ -790,7 +794,7 @@ def _get_red_lines(
             result.append(
                 {
                     "geom_wkt": geom_wkt_val,
-                    "intersection_area_sqm": intersection_area_sqm,
+                    "intersection_length_m": intersection_length_m,
                     "distance_m": distance_m,
                 }
             )

backend/tests/services/test_quarter_dump_lookup.py

@@ -297,13 +297,13 @@ def test_get_opportunity_parcels_db_exception_returns_empty() -> None:
 
 
 def test_get_red_lines_intersects() -> None:
-    """Red line intersecting parcel → intersection_area_sqm filled, distance_m=None."""
+    """Red line intersecting parcel → intersection_length_m filled, distance_m=None."""
     rows: list[tuple[Any, ...]] = [
-        # (geom_wkt, does_intersect, intersection_area_sqm, distance_m)
+        # (geom_wkt, does_intersect, intersection_length_m, distance_m)
         (
             "LINESTRING(0 0, 1 1)",
             True,
-            500.0,
+            45.3,  # длина пересечения в метрах
             0.0,  # intersecting → distance_m becomes None in result
         ),
     ]
@@ -314,14 +314,14 @@ def test_get_red_lines_intersects() -> None:
     assert len(result) == 1
     r = result[0]
     assert r["geom_wkt"] == "LINESTRING(0 0, 1 1)"
-    assert r["intersection_area_sqm"] == 500.0
+    assert r["intersection_length_m"] == 45.3
     assert r["distance_m"] is None  # null when intersecting
 
 
 def test_get_red_lines_nearby_only() -> None:
-    """Red line nearby only (не intersect) → distance_m filled, intersection_area_sqm=None."""
+    """Red line nearby only (не intersect) → distance_m filled, intersection_length_m=None."""
     rows: list[tuple[Any, ...]] = [
-        # (geom_wkt, does_intersect, intersection_area_sqm, distance_m)
+        # (geom_wkt, does_intersect, intersection_length_m, distance_m)
         (
             "LINESTRING(10 10, 20 20)",
             False,
@@ -335,10 +335,18 @@ def test_get_red_lines_nearby_only() -> None:
 
     assert len(result) == 1
     r = result[0]
-    assert r["intersection_area_sqm"] is None
+    assert r["intersection_length_m"] is None
     assert r["distance_m"] == 85.5
 
 
+def test_get_red_lines_db_exception_returns_empty() -> None:
+    """DB exception → пустой список (не propagate)."""
+    db = MagicMock()
+    db.execute.side_effect = Exception("DB connection lost")
+    result = _get_red_lines(db, "66:41:0204016", "POLYGON((0 0,1 0,1 1,0 0))")
+    assert result == []
+
+
 def test_get_red_lines_empty() -> None:
     """Нет red lines features — пустой список."""
     db = _make_mock_db_with_rows([])

data/sql/98_nspd_quarter_dumps_opportunity_flag.sql

@@ -1,4 +1,4 @@
--- 89_nspd_quarter_dumps_opportunity_flag.sql
+-- 98_nspd_quarter_dumps_opportunity_flag.sql
 -- Context : TIER 4 opportunity denorm columns for nspd_quarter_dumps.
 --           Enables fast map filter "find quarters with auction parcels" without
 --           unpacking features_json JSONB on every query.

frontend/src/components/site-finder/NspdRedLinesBlock.tsx

@@ -6,10 +6,10 @@ interface Props {
   redLines: RedLine[] | null | undefined;
 }
 
-function formatArea(sqm: number | null): string | null {
-  if (sqm === null) return null;
-  if (sqm >= 10000) return `${(sqm / 10000).toFixed(2)} га`;
-  return `${Math.round(sqm).toLocaleString("ru-RU")} м²`;
+function formatLength(m: number | null): string | null {
+  if (m === null) return null;
+  if (m >= 1000) return `${(m / 1000).toFixed(2)} км`;
+  return `${Math.round(m)} м`;
 }
 
 function formatDistance(m: number | null): string | null {
@@ -25,8 +25,8 @@ export function NspdRedLinesBlock({ redLines }: Props) {
     return null;
   }
 
-  const intersecting = lines.filter((l) => l.intersection_area_sqm !== null);
-  const nearbyOnly = lines.filter((l) => l.intersection_area_sqm === null);
+  const intersecting = lines.filter((l) => l.intersection_length_m !== null);
+  const nearbyOnly = lines.filter((l) => l.intersection_length_m === null);
   const hasIntersect = intersecting.length > 0;
 
   return (
@@ -64,11 +64,11 @@ export function NspdRedLinesBlock({ redLines }: Props) {
             </div>
             <div style={{ fontSize: 12, color: "#7f1d1d", marginTop: 4 }}>
               {intersecting.map((l, idx) => {
-                const areaStr = formatArea(l.intersection_area_sqm);
+                const lenStr = formatLength(l.intersection_length_m);
                 return (
                   <div key={idx}>
                     Линия {idx + 1}
-                    {areaStr ? `: пересечение ${areaStr}` : ""}
+                    {lenStr ? `: длина пересечения ${lenStr}` : ""}
                   </div>
                 );
               })}

frontend/src/types/nspd.ts

@@ -59,7 +59,7 @@ export interface OpportunityParcel {
 
 export interface RedLine {
   geom_wkt: string | null;
-  intersection_area_sqm: number | null; // null if only nearby, not intersecting
+  intersection_length_m: number | null; // null if only nearby, not intersecting
   distance_m: number | null; // null if intersecting
 }