feat: Initialize frontend and backend structure with essential configurations

- Added TypeScript build info for frontend.
- Created Vite configuration for React application.
- Implemented pre-commit hook to run checks before commits.
- Set up PostgreSQL Dockerfile with PostGIS support and initialization scripts.
- Added database creation script for PostgreSQL with necessary extensions.
- Established Python project configuration with dependencies and development tools.
- Developed pre-commit script to enforce code quality checks for backend and frontend.
- Created PowerShell script to set up Git hooks path.

backend/app/services/network.py

@@ -0,0 +1,157 @@
+"""Domain services for railway network aggregation."""
+
+from datetime import datetime, timezone
+from decimal import Decimal
+from typing import Iterable, cast
+
+from geoalchemy2.elements import WKBElement, WKTElement
+from geoalchemy2.shape import to_shape
+try:  # pragma: no cover - optional dependency guard
+    from shapely.geometry import Point  # type: ignore
+except ImportError:  # pragma: no cover - allow running without shapely at import time
+    Point = None  # type: ignore[assignment]
+
+from sqlalchemy.orm import Session
+
+from backend.app.models import StationModel, TrackModel, TrainModel
+from backend.app.repositories import StationRepository, TrackRepository, TrainRepository
+
+
+def _timestamp() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+def _fallback_snapshot() -> dict[str, list[dict[str, object]]]:
+    now = _timestamp()
+    stations = [
+        StationModel(
+            id="station-1",
+            name="Central",
+            latitude=52.520008,
+            longitude=13.404954,
+            created_at=now,
+            updated_at=now,
+        ),
+        StationModel(
+            id="station-2",
+            name="Harbor",
+            latitude=53.551086,
+            longitude=9.993682,
+            created_at=now,
+            updated_at=now,
+        ),
+    ]
+
+    tracks = [
+        TrackModel(
+            id="track-1",
+            start_station_id="station-1",
+            end_station_id="station-2",
+            length_meters=289000.0,
+            max_speed_kph=230.0,
+            created_at=now,
+            updated_at=now,
+        )
+    ]
+
+    trains = [
+        TrainModel(
+            id="train-1",
+            designation="ICE 123",
+            capacity=400,
+            max_speed_kph=300.0,
+            operating_track_ids=[track.id for track in tracks],
+            created_at=now,
+            updated_at=now,
+        )
+    ]
+
+    return _serialize_snapshot(stations, tracks, trains)
+
+
+def _serialize_snapshot(
+    stations: Iterable[StationModel],
+    tracks: Iterable[TrackModel],
+    trains: Iterable[TrainModel],
+) -> dict[str, list[dict[str, object]]]:
+    return {
+        "stations": [station.model_dump(by_alias=True) for station in stations],
+        "tracks": [track.model_dump(by_alias=True) for track in tracks],
+        "trains": [train.model_dump(by_alias=True) for train in trains],
+    }
+
+
+def _to_float(value: Decimal | float | int | None, default: float = 0.0) -> float:
+    if value is None:
+        return default
+    if isinstance(value, Decimal):
+        return float(value)
+    return float(value)
+
+
+def get_network_snapshot(session: Session) -> dict[str, list[dict[str, object]]]:
+    station_repo = StationRepository(session)
+    track_repo = TrackRepository(session)
+    train_repo = TrainRepository(session)
+
+    stations_entities = station_repo.list_active()
+    tracks_entities = track_repo.list_all()
+    trains_entities = train_repo.list_all()
+
+    if not stations_entities and not tracks_entities and not trains_entities:
+        return _fallback_snapshot()
+
+    station_models: list[StationModel] = []
+    for station in stations_entities:
+        location = station.location
+        geom = (
+            to_shape(cast(WKBElement | WKTElement, location))
+            if location is not None and Point is not None
+            else None
+        )
+        if Point is not None and geom is not None and isinstance(geom, Point):
+            latitude = float(geom.y)
+            longitude = float(geom.x)
+        else:
+            latitude = 0.0
+            longitude = 0.0
+        station_models.append(
+            StationModel(
+                id=str(station.id),
+                name=station.name,
+                latitude=latitude,
+                longitude=longitude,
+                created_at=cast(datetime, station.created_at),
+                updated_at=cast(datetime, station.updated_at),
+            )
+        )
+
+    track_models: list[TrackModel] = []
+    for track in tracks_entities:
+        track_models.append(
+            TrackModel(
+                id=str(track.id),
+                start_station_id=str(track.start_station_id),
+                end_station_id=str(track.end_station_id),
+                length_meters=_to_float(track.length_meters),
+                max_speed_kph=_to_float(track.max_speed_kph),
+                created_at=cast(datetime, track.created_at),
+                updated_at=cast(datetime, track.updated_at),
+            )
+        )
+
+    train_models: list[TrainModel] = []
+    for train in trains_entities:
+        train_models.append(
+            TrainModel(
+                id=str(train.id),
+                designation=train.designation,
+                capacity=train.capacity,
+                max_speed_kph=_to_float(train.max_speed_kph),
+                operating_track_ids=[],
+                created_at=cast(datetime, train.created_at),
+                updated_at=cast(datetime, train.updated_at),
+            )
+        )
+
+    return _serialize_snapshot(station_models, track_models, train_models)