Initial: Rust-Backend mit Clean Architecture (domain/application/infrastructure/api)

Vier-Crate-Workspace mit:
- Domain: Account, Car, Tour, Delivery, DeliveryItem, DeliveryNote, Customer,
  Article, Warehouse, ScanState, AuditAction — alle mit serde + feature-gated
  utoipa::ToSchema.
- Application: Ports (TourRepository, DeliveryRepository, ScanRepository,
  DeliveryNoteRepository, CarRepository, AuthService) und Use Cases.
- Infrastructure: Postgres-Adapter via sqlx (PgTourRepository etc.) +
  Keycloak-AuthService mit JWKS-Cache + OIDC-Discovery.
- API: Axum 0.8, utoipa-OpenAPI + Swagger-UI, JWT-Bearer-Middleware,
  AuthenticatedUser-Extractor.

Endpoints:
- GET /me/tours/today, /tours/{id}, /accounts/{pn}, /me/cars, /health
- POST /sync/tour, /scans (bulk + idempotent via clientScanId),
  /deliveries/{id}/{hold,resume,cancel,complete,notes}, /me/cars
- PUT /tours/{id}/delivery-order, /deliveries/{id}/assigned-car, /me/cars/{id}
- PATCH /me/cars/{id}

Datenmodell:
- 6 Migrationen (accounts, tours/deliveries/items + Stammdaten,
  scan_audit mit clientScanId-UNIQUE, state_reason refactor,
  delivery_notes, cars + FKs nachziehen).
- Business-stabile Beleg-Keys (belegart_id, belegnummer) für ERP-Sync.
- Append-only scan_audit + embedded scan_state als doppelte Wahrheit.

Dev-Setup:
- docker-compose mit Postgres 17 + Keycloak 26
- Keycloak-Realm 'holzleitner' mit Public-Client (PKCE), Testfahrer
  (PN 1001) + Audience-/Personalnummer-Mapper

crates/api/src/routes/cars.rs

@@ -0,0 +1,108 @@
+use axum::Json;
+use axum::Router;
+use axum::extract::{Path, Query, State};
+use axum::routing::{get, patch};
+use holzleitner_application::dto::{
+    CarResponse, CarsList, CreateCarRequest, UpdateCarRequest,
+};
+use serde::Deserialize;
+use uuid::Uuid;
+
+use crate::error::ApiError;
+use crate::extractors::AuthenticatedUser;
+use crate::state::AppState;
+
+pub fn router() -> Router<AppState> {
+    Router::new()
+        .route("/me/cars", get(list_my_cars).post(create_my_car))
+        .route("/me/cars/{car_id}", patch(update_my_car))
+}
+
+/// Query-Parameter für `GET /me/cars`.
+#[derive(Debug, Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct ListCarsQuery {
+    /// Default `false` — Endpoint liefert standardmäßig auch
+    /// deaktivierte Fahrzeuge **nicht** mit.
+    #[serde(default)]
+    pub include_inactive: bool,
+}
+
+/// Listet die Fahrzeuge des angemeldeten Fahrers.
+#[utoipa::path(
+    get,
+    path = "/me/cars",
+    tag = "cars",
+    params(
+        ("includeInactive" = Option<bool>, Query, description = "Wenn true, werden inaktive Fahrzeuge mitgeliefert (default: false)")
+    ),
+    responses(
+        (status = 200, description = "Fahrzeuge des Fahrers", body = CarsList),
+        (status = 401, description = "Authentifizierung fehlgeschlagen")
+    ),
+    security(("bearer_auth" = []))
+)]
+pub async fn list_my_cars(
+    State(state): State<AppState>,
+    AuthenticatedUser(claims): AuthenticatedUser,
+    Query(query): Query<ListCarsQuery>,
+) -> Result<Json<CarsList>, ApiError> {
+    let cars = state
+        .list_my_cars
+        .execute(claims.personalnummer, query.include_inactive)
+        .await?;
+    Ok(Json(CarsList { cars }))
+}
+
+/// Legt ein neues Fahrzeug für den angemeldeten Fahrer an.
+#[utoipa::path(
+    post,
+    path = "/me/cars",
+    tag = "cars",
+    request_body = CreateCarRequest,
+    responses(
+        (status = 200, description = "Fahrzeug angelegt", body = CarResponse),
+        (status = 400, description = "Validierungsfehler (z. B. doppeltes Kennzeichen)"),
+        (status = 401, description = "Authentifizierung fehlgeschlagen")
+    ),
+    security(("bearer_auth" = []))
+)]
+pub async fn create_my_car(
+    State(state): State<AppState>,
+    AuthenticatedUser(claims): AuthenticatedUser,
+    Json(req): Json<CreateCarRequest>,
+) -> Result<Json<CarResponse>, ApiError> {
+    let car = state
+        .create_my_car
+        .execute(claims.personalnummer, req)
+        .await?;
+    Ok(Json(CarResponse { car }))
+}
+
+/// Aktualisiert ein Fahrzeug (Kennzeichen ändern / deaktivieren).
+#[utoipa::path(
+    patch,
+    path = "/me/cars/{car_id}",
+    tag = "cars",
+    params(("car_id" = Uuid, Path)),
+    request_body = UpdateCarRequest,
+    responses(
+        (status = 200, description = "Fahrzeug aktualisiert", body = CarResponse),
+        (status = 400, description = "Validierungsfehler"),
+        (status = 401, description = "Authentifizierung fehlgeschlagen"),
+        (status = 404, description = "Fahrzeug nicht gefunden oder gehört nicht zu diesem Account")
+    ),
+    security(("bearer_auth" = []))
+)]
+pub async fn update_my_car(
+    State(state): State<AppState>,
+    AuthenticatedUser(claims): AuthenticatedUser,
+    Path(car_id): Path<Uuid>,
+    Json(req): Json<UpdateCarRequest>,
+) -> Result<Json<CarResponse>, ApiError> {
+    let car = state
+        .update_my_car
+        .execute(car_id, claims.personalnummer, req)
+        .await?;
+    Ok(Json(CarResponse { car }))
+}