Gatehouse v0.1.0

First public release of Gatehouse: tenant-scoped access requests, role-aware approvals, idempotent creation, optimistic concurrency, hash-linked audit evidence, Prometheus health signals, a React review desk, and production deployment blueprints for Docker, Kubernetes, and Terraform.\n\nContainer images:\n- ghcr.io/kyan9400/gatehouse-api:v0.1.0\n- ghcr.io/kyan9400/gatehouse-web:v0.1.0