Add vector change detection foundation

backend/app/schemas/__init__.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from .common import ApiErrorEnvelope, ApiErrorItem, Envelope, PaginationEnvelope
 from .project import ProjectCreate, ProjectList, ProjectRead, ProjectUpdate
 from .area import AreaCreate, AreaList, AreaRead, AreaUpdate
+from .analysis import ChangeDetectionRequest, ChangeDetectionSummary
 from .dataset import DatasetCreateResponse, DatasetList
 from .detection import (
     DetectionListResponse,
@@ -87,6 +88,8 @@ __all__ = [
     "AreaRead",
     "AreaUpdate",
     "AreaList",
+    "ChangeDetectionRequest",
+    "ChangeDetectionSummary",
     "DatasetCreateResponse",
     "DatasetList",
     "DetectionListResponse",

backend/app/schemas/analysis.py

@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+from datetime import datetime
+from uuid import UUID
+
+from pydantic import BaseModel, Field
+
+
+class ChangeDetectionRequest(BaseModel):
+    source_dataset_id: UUID
+    target_dataset_id: UUID
+    iou_threshold: float = Field(default=0.8, ge=0.0, le=1.0)
+    include_unchanged: bool = True
+
+
+class ChangeDetectionSummary(BaseModel):
+    source_dataset_id: UUID
+    target_dataset_id: UUID
+    source_feature_count: int
+    target_feature_count: int
+    added_count: int
+    removed_count: int
+    unchanged_count: int
+    iou_threshold: float
+    warnings: list[str] = Field(default_factory=list)
+    generated_at: datetime
+    geojson: dict