Add map area selection extraction

backend/app/schemas/operations.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field, field_validator
 
 
 class VectorOperationResult(BaseModel):
@@ -191,3 +191,31 @@ class VectorStatsResponse(BaseModel):
     geometry_type_summary: dict[str, int]
     bounds_json: dict | None
     crs: str | None = None
+
+
+class VectorSelectionBBox(BaseModel):
+    min_x: float
+    min_y: float
+    max_x: float
+    max_y: float
+    crs: str = "EPSG:4326"
+
+    @field_validator("crs")
+    @classmethod
+    def validate_crs(cls, value: str) -> str:
+        if value.upper() != "EPSG:4326":
+            raise ValueError("Only EPSG:4326 bbox selection is supported")
+        return "EPSG:4326"
+
+
+class VectorSelectionRequest(BaseModel):
+    bbox: VectorSelectionBBox
+    limit: int = Field(default=100, ge=1, le=1000)
+
+
+class VectorSelectionResponse(BaseModel):
+    selection_bbox: VectorSelectionBBox
+    feature_count: int
+    limit: int
+    truncated: bool
+    geojson: dict