Remove POST /apps, DELETE /apps/{id}, and POST /apps/{id}/deploy from
the API v1 route group. These endpoints used cookie-based session auth
without CSRF protection, creating a CSRF vulnerability.
Read-only endpoints (GET /apps, GET /apps/{id}, GET /apps/{id}/deployments),
login, and whoami are retained.
Removed handlers: HandleAPICreateApp, HandleAPIDeleteApp,
HandleAPITriggerDeploy, along with apiCreateRequest struct and
validateCreateRequest function.
Updated tests to use service layer directly for app creation in
remaining read-only endpoint tests.
