M1: implement operational core

Demo auth, seed import/reset, dashboard, vehicle/booking list+detail, audit trail. Backend: 19 tests passing, ruff clean. Frontend: React Router shell, typed API client, responsive pages. Verified end-to-end via curl and browser.

backend/pyproject.toml

@@ -34,7 +34,8 @@ asyncio_mode = "auto"
 
 [tool.ruff]
 line-length = 100
-extend-exclude = ["alembic/versions"]
+extend-exclude = ["alembic/versions", "seed"]
 
 [tool.ruff.lint]
 select = ["E", "F", "I", "B", "UP"]
+ignore = ["B008"]