Add unit tests for station service and enhance documentation

- Introduced unit tests for the station service, covering creation, updating, and archiving of stations.
- Added detailed building block view documentation outlining the architecture of the Rail Game system.
- Created runtime view documentation illustrating key user interactions and system behavior.
- Developed concepts documentation detailing domain models, architectural patterns, and security considerations.
- Updated architecture documentation to reference new detailed sections for building block and runtime views.

backend/app/models/base.py

@@ -42,6 +42,10 @@ class StationModel(IdentifiedModel[str]):
     name: str
     latitude: float
     longitude: float
+    code: str | None = None
+    osm_id: str | None = None
+    elevation_m: float | None = None
+    is_active: bool = True
 
 
 class TrackModel(IdentifiedModel[str]):
@@ -68,6 +72,16 @@ class StationCreate(CamelModel):
     is_active: bool = True
 
 
+class StationUpdate(CamelModel):
+    name: str | None = None
+    latitude: float | None = None
+    longitude: float | None = None
+    osm_id: str | None = None
+    code: str | None = None
+    elevation_m: float | None = None
+    is_active: bool | None = None
+
+
 class TrackCreate(CamelModel):
     start_station_id: str
     end_station_id: str