feat: Add combined track functionality with repository and service layers

- Introduced CombinedTrackModel, CombinedTrackCreate, and CombinedTrackRepository for managing combined tracks.
- Implemented logic to create combined tracks based on existing tracks between two stations.
- Added methods to check for existing combined tracks and retrieve constituent track IDs.
- Enhanced TrackModel and TrackRepository to support OSM ID and track updates.
- Created migration scripts for adding combined tracks table and OSM ID to tracks.
- Updated services and API endpoints to handle combined track operations.
- Added tests for combined track creation, repository methods, and API interactions.

backend/app/models/base.py

@@ -51,13 +51,24 @@ class StationModel(IdentifiedModel[str]):
 class TrackModel(IdentifiedModel[str]):
     start_station_id: str
     end_station_id: str
-    length_meters: float
-    max_speed_kph: float
+    length_meters: float | None = None
+    max_speed_kph: float | None = None
     status: str | None = None
     is_bidirectional: bool = True
     coordinates: list[tuple[float, float]] = Field(default_factory=list)
 
 
+class CombinedTrackModel(IdentifiedModel[str]):
+    start_station_id: str
+    end_station_id: str
+    length_meters: float | None = None
+    max_speed_kph: int | None = None
+    status: str | None = None
+    is_bidirectional: bool = True
+    coordinates: list[tuple[float, float]] = Field(default_factory=list)
+    constituent_track_ids: list[str] = Field(default_factory=list)
+
+
 class TrainModel(IdentifiedModel[str]):
     designation: str
     capacity: int
@@ -89,6 +100,31 @@ class TrackCreate(CamelModel):
     start_station_id: str
     end_station_id: str
     coordinates: Sequence[tuple[float, float]]
+    osm_id: str | None = None
+    name: str | None = None
+    length_meters: float | None = None
+    max_speed_kph: int | None = None
+    is_bidirectional: bool = True
+    status: str = "planned"
+
+
+class TrackUpdate(CamelModel):
+    start_station_id: str | None = None
+    end_station_id: str | None = None
+    coordinates: Sequence[tuple[float, float]] | None = None
+    osm_id: str | None = None
+    name: str | None = None
+    length_meters: float | None = None
+    max_speed_kph: int | None = None
+    is_bidirectional: bool | None = None
+    status: str | None = None
+
+
+class CombinedTrackCreate(CamelModel):
+    start_station_id: str
+    end_station_id: str
+    coordinates: Sequence[tuple[float, float]]
+    constituent_track_ids: list[str]
     name: str | None = None
     length_meters: float | None = None
     max_speed_kph: int | None = None