feat: add Playwright configuration and initial e2e test for authentication

- Created Playwright configuration file to set up testing environment.
- Added a new e2e test for user authentication in login.spec.ts.
- Updated tsconfig.node.json to include playwright.config.ts.
- Enhanced vite.config.ts to include API proxying for backend integration.
- Added a placeholder for last run test results in .last-run.json.

backend/app/db/unit_of_work.py

@@ -0,0 +1,62 @@
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Optional
+
+from sqlalchemy.orm import Session
+
+from backend.app.db.session import SessionLocal
+from backend.app.repositories import (
+    StationRepository,
+    TrainRepository,
+    TrainScheduleRepository,
+    TrackRepository,
+    UserRepository,
+)
+
+
+class SqlAlchemyUnitOfWork:
+    """Coordinate transactional work across repositories."""
+
+    def __init__(self, session_factory: Callable[[], Session] = SessionLocal) -> None:
+        self._session_factory = session_factory
+        self.session: Optional[Session] = None
+        self._committed = False
+        self.users: UserRepository
+        self.stations: StationRepository
+        self.tracks: TrackRepository
+        self.trains: TrainRepository
+        self.train_schedules: TrainScheduleRepository
+
+    def __enter__(self) -> "SqlAlchemyUnitOfWork":
+        self.session = self._session_factory()
+        self.users = UserRepository(self.session)
+        self.stations = StationRepository(self.session)
+        self.tracks = TrackRepository(self.session)
+        self.trains = TrainRepository(self.session)
+        self.train_schedules = TrainScheduleRepository(self.session)
+        return self
+
+    def __exit__(self, exc_type, exc, _tb) -> None:
+        try:
+            if exc:
+                self.rollback()
+            elif not self._committed:
+                self.commit()
+        finally:
+            if self.session is not None:
+                self.session.close()
+                self.session = None
+                self._committed = False
+
+    def commit(self) -> None:
+        if self.session is None:
+            raise RuntimeError("Unit of work is not active")
+        self.session.commit()
+        self._committed = True
+
+    def rollback(self) -> None:
+        if self.session is None:
+            return
+        self.session.rollback()
+        self._committed = False

backend/app/models/__init__.py

@@ -12,8 +12,10 @@ from .base import (
 	StationModel,
 	TrackCreate,
 	TrackModel,
+	TrainScheduleCreate,
 	TrainCreate,
 	TrainModel,
+	UserCreate,
 	to_camel,
 )
 
@@ -29,7 +31,9 @@ __all__ = [
 	"StationModel",
 	"TrackCreate",
 	"TrackModel",
+	"TrainScheduleCreate",
 	"TrainCreate",
 	"TrainModel",
+	"UserCreate",
 	"to_camel",
 ]

backend/app/models/base.py

@@ -85,3 +85,21 @@ class TrainCreate(CamelModel):
     operator_id: str | None = None
     home_station_id: str | None = None
     consist: str | None = None
+
+
+class TrainScheduleCreate(CamelModel):
+    train_id: str
+    station_id: str
+    sequence_index: int
+    scheduled_arrival: datetime | None = None
+    scheduled_departure: datetime | None = None
+    dwell_seconds: int | None = None
+
+
+class UserCreate(CamelModel):
+    username: str
+    password_hash: str
+    email: str | None = None
+    full_name: str | None = None
+    role: str = "player"
+    preferences: str | None = None

backend/app/repositories/__init__.py

@@ -1,11 +1,15 @@
 """Repository abstractions for database access."""
 
 from backend.app.repositories.stations import StationRepository
+from backend.app.repositories.train_schedules import TrainScheduleRepository
 from backend.app.repositories.tracks import TrackRepository
 from backend.app.repositories.trains import TrainRepository
+from backend.app.repositories.users import UserRepository
 
 __all__ = [
     "StationRepository",
+    "TrainScheduleRepository",
     "TrackRepository",
     "TrainRepository",
+    "UserRepository",
 ]

backend/app/repositories/train_schedules.py

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+import sqlalchemy as sa
+from uuid import UUID
+from sqlalchemy.orm import Session
+
+from backend.app.db.models import TrainSchedule
+from backend.app.models import TrainScheduleCreate
+from backend.app.repositories.base import BaseRepository
+
+
+class TrainScheduleRepository(BaseRepository[TrainSchedule]):
+    """Persistence operations for train timetables."""
+
+    model = TrainSchedule
+
+    def __init__(self, session: Session) -> None:
+        super().__init__(session)
+
+    @staticmethod
+    def _ensure_uuid(value: UUID | str) -> UUID:
+        if isinstance(value, UUID):
+            return value
+        return UUID(str(value))
+
+    def list_for_train(self, train_id: UUID | str) -> list[TrainSchedule]:
+        identifier = self._ensure_uuid(train_id)
+        statement = (
+            sa.select(self.model)
+            .where(self.model.train_id == identifier)
+            .order_by(self.model.sequence_index.asc())
+        )
+        return list(self.session.scalars(statement))
+
+    def create(self, data: TrainScheduleCreate) -> TrainSchedule:
+        schedule = TrainSchedule(
+            train_id=self._ensure_uuid(data.train_id),
+            station_id=self._ensure_uuid(data.station_id),
+            sequence_index=data.sequence_index,
+            scheduled_arrival=data.scheduled_arrival,
+            scheduled_departure=data.scheduled_departure,
+            dwell_seconds=data.dwell_seconds,
+        )
+        self.session.add(schedule)
+        return schedule

backend/app/repositories/users.py

@@ -0,0 +1,37 @@
+from __future__ import annotations
+
+import sqlalchemy as sa
+from sqlalchemy.orm import Session
+
+from backend.app.db.models import User
+from backend.app.models import UserCreate
+from backend.app.repositories.base import BaseRepository
+
+
+class UserRepository(BaseRepository[User]):
+    """Data access helpers for user accounts."""
+
+    model = User
+
+    def __init__(self, session: Session) -> None:
+        super().__init__(session)
+
+    def get_by_username(self, username: str) -> User | None:
+        statement = sa.select(self.model).where(sa.func.lower(self.model.username) == username.lower())
+        return self.session.scalar(statement)
+
+    def list_recent(self, limit: int = 50) -> list[User]:
+        statement = sa.select(self.model).order_by(self.model.created_at.desc()).limit(limit)
+        return list(self.session.scalars(statement))
+
+    def create(self, data: UserCreate) -> User:
+        user = User(
+            username=data.username,
+            email=data.email,
+            full_name=data.full_name,
+            password_hash=data.password_hash,
+            role=data.role,
+            preferences=data.preferences,
+        )
+        self.session.add(user)
+        return user

backend/app/services/network.py

@@ -12,6 +12,7 @@ except ImportError:  # pragma: no cover - allow running without shapely at impor
     Point = None  # type: ignore[assignment]
 
 from sqlalchemy.orm import Session
+from sqlalchemy.exc import SQLAlchemyError
 
 from backend.app.models import StationModel, TrackModel, TrainModel
 from backend.app.repositories import StationRepository, TrackRepository, TrainRepository
@@ -94,9 +95,13 @@ def get_network_snapshot(session: Session) -> dict[str, list[dict[str, object]]]
     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()
+    try:
+        stations_entities = station_repo.list_active()
+        tracks_entities = track_repo.list_all()
+        trains_entities = train_repo.list_all()
+    except SQLAlchemyError:
+        session.rollback()
+        return _fallback_snapshot()
 
     if not stations_entities and not tracks_entities and not trains_entities:
         return _fallback_snapshot()

backend/tests/test_repositories.py

@@ -1,17 +1,40 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import Any, List
+from datetime import datetime, timezone
+from typing import Any, List, cast
+from uuid import uuid4
 
 import pytest
 
-from backend.app.models import StationCreate, TrackCreate, TrainCreate
-from backend.app.repositories import StationRepository, TrackRepository, TrainRepository
+from backend.app.db.models import TrainSchedule, User
+from backend.app.db.unit_of_work import SqlAlchemyUnitOfWork
+from backend.app.models import (
+    StationCreate,
+    TrackCreate,
+    TrainCreate,
+    TrainScheduleCreate,
+    UserCreate,
+)
+from backend.app.repositories import (
+    StationRepository,
+    TrackRepository,
+    TrainRepository,
+    TrainScheduleRepository,
+    UserRepository,
+)
+from sqlalchemy.orm import Session
 
 
 @dataclass
 class DummySession:
     added: List[Any] = field(default_factory=list)
+    scalars_result: List[Any] = field(default_factory=list)
+    scalar_result: Any = None
+    statements: List[Any] = field(default_factory=list)
+    committed: bool = False
+    rolled_back: bool = False
+    closed: bool = False
 
     def add(self, instance: Any) -> None:
         self.added.append(instance)
@@ -19,12 +42,26 @@ class DummySession:
     def add_all(self, instances: list[Any]) -> None:
         self.added.extend(instances)
 
-    def scalars(self, _statement: Any) -> list[Any]:  # pragma: no cover - not used here
-        return []
+    def scalars(self, statement: Any) -> list[Any]:
+        self.statements.append(statement)
+        return list(self.scalars_result)
+
+    def scalar(self, statement: Any) -> Any:
+        self.statements.append(statement)
+        return self.scalar_result
 
     def flush(self, _objects: list[Any] | None = None) -> None:  # pragma: no cover - optional
         return None
 
+    def commit(self) -> None:  # pragma: no cover - optional
+        self.committed = True
+
+    def rollback(self) -> None:  # pragma: no cover - optional
+        self.rolled_back = True
+
+    def close(self) -> None:  # pragma: no cover - optional
+        self.closed = True
+
 
 def test_station_repository_create_generates_geometry() -> None:
     session = DummySession()
@@ -104,3 +141,96 @@ def test_train_repository_create_supports_optional_ids() -> None:
     assert train.designation == "ICE 123"
     assert str(train.home_station_id).endswith("1")
     assert train.operator_id is None
+
+
+def test_user_repository_create_persists_user() -> None:
+    session = DummySession()
+    repo = UserRepository(session)  # type: ignore[arg-type]
+
+    user = repo.create(
+        UserCreate(
+            username="demo",
+            password_hash="hashed",
+            email="demo@example.com",
+            full_name="Demo Engineer",
+            role="admin",
+        )
+    )
+
+    assert session.added and session.added[0] is user
+    assert user.username == "demo"
+    assert user.role == "admin"
+
+
+def test_user_repository_get_by_username_is_case_insensitive() -> None:
+    existing = User(username="Demo", password_hash="hashed", role="player")
+    session = DummySession(scalar_result=existing)
+    repo = UserRepository(session)  # type: ignore[arg-type]
+
+    result = repo.get_by_username("demo")
+
+    assert result is existing
+    assert session.statements
+
+
+def test_train_schedule_repository_create_converts_identifiers() -> None:
+    session = DummySession()
+    repo = TrainScheduleRepository(session)  # type: ignore[arg-type]
+    train_id = uuid4()
+    station_id = uuid4()
+
+    schedule = repo.create(
+        TrainScheduleCreate(
+            train_id=str(train_id),
+            station_id=str(station_id),
+            sequence_index=1,
+            scheduled_arrival=datetime.now(timezone.utc),
+            dwell_seconds=90,
+        )
+    )
+
+    assert session.added and session.added[0] is schedule
+    assert schedule.train_id == train_id
+    assert schedule.station_id == station_id
+
+
+def test_train_schedule_repository_list_for_train_orders_results() -> None:
+    train_id = uuid4()
+    schedules = [
+        TrainSchedule(train_id=train_id, station_id=uuid4(), sequence_index=2),
+        TrainSchedule(train_id=train_id, station_id=uuid4(), sequence_index=1),
+    ]
+    session = DummySession(scalars_result=schedules)
+    repo = TrainScheduleRepository(session)  # type: ignore[arg-type]
+
+    result = repo.list_for_train(train_id)
+
+    assert result == schedules
+    statement = session.statements[-1]
+    assert getattr(statement, "_order_by_clauses", ())
+
+
+def test_unit_of_work_commits_and_closes_session() -> None:
+    session = DummySession()
+    uow = SqlAlchemyUnitOfWork(lambda: cast(Session, session))
+
+    with uow as active:
+        active.users.create(
+            UserCreate(username="demo", password_hash="hashed")
+        )
+        active.commit()
+
+    assert session.committed
+    assert session.closed
+
+
+def test_unit_of_work_rolls_back_on_exception() -> None:
+    session = DummySession()
+    uow = SqlAlchemyUnitOfWork(lambda: cast(Session, session))
+
+    with pytest.raises(RuntimeError):
+        with uow:
+            raise RuntimeError("boom")
+
+    assert session.rolled_back
+    assert session.closed