rail-kubernetes Docs

app-toml-contract.md — canonical workload declaration contract for the rail
overlay-repo-pattern.md — compatibility-era overlay pattern on the path to rapp-*
canary-helm-template.md — stage-aware canary/stable chart pattern
deployment-lifecycle.md — canonical stage 1 / 2 / 3 lifecycle contract
stage2-deploy-observe.md — stage 2 command behavior contract
promote-rollback-onboarding.md — representative lifecycle command path
railiance-run-command.md — stage 1 command behavior contract
wave-1-contract.md — current rail contract and boundary summary
source-import-plan.md — source material and migration direction from existing repos