feat: wire the Doormile endpoint onto the server's actual code

f804791 added app/routes/doormile.py against a base that predated the
Valhalla work. Rebasing it onto 9ef2f61 rewires it to what is really
running, without disturbing anything the server had: the RoadMatrix
probe, road_backend_status and the VALHALLA_URL switch are all intact.

The one thing the endpoint depends on is unchanged --
optimize_provider_payload(orders, start_coords=None) has the same
signature in the server's optimizer as in the version it was written
against -- so passing the kitchen through as the run's start still
works. Tests re-run against the server's code: all pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/main.py

@@ -28,7 +28,7 @@ from app.core.exception_handlers import (
 )
 from app.core.exceptions import APIException
 from app.middleware.request_id import RequestIDMiddleware
-from app.routes import cache_router, health_router, ml_router, ml_web_router, optimization_router, batch_analytics_router, riders_router
+from app.routes import cache_router, health_router, ml_router, ml_web_router, optimization_router, batch_analytics_router, riders_router, doormile_router
 
 # ---------------------------------------------------------------------------
 # Logging
@@ -183,6 +183,7 @@ app.include_router(ml_router)
 app.include_router(ml_web_router)
 app.include_router(batch_analytics_router)
 app.include_router(riders_router)
+app.include_router(doormile_router)
 
 
 @app.get("/", tags=["Root"])

app/routes/__init__.py

@@ -6,6 +6,7 @@ from .cache import router as cache_router
 from .ml_admin import router as ml_router, web_router as ml_web_router
 from .batch_analytics import router as batch_analytics_router
 from .riders import router as riders_router
+from .doormile import router as doormile_router
 
 __all__ = [
     "optimization_router",
@@ -15,4 +16,5 @@ __all__ = [
     "ml_web_router",
     "batch_analytics_router",
     "riders_router",
+    "doormile_router",
 ]