Adds model, repo, controller, and request classes for Vehicle and Convoy.
Registers routes for vehicles and convoys, updates client store.
Adds front‑end files to list, add, edit vehicles.
Cleans up console logging from client store.
Add user management endpoints and link employees to existing users
through `user_id`, including API resources, validation, repository
support, and database migrations.
Introduce a two-step login flow that checks email first and lets users
without a password create one before signing in.
Update the employee detail UI with a dedicated user tab and refresh the
employee and intervention side navigation to support the new account
management flow.
