feat(dev): add local operator development stack

[jmgilman]

Summary

• add Proto-managed kind and ctlptl alongside tilt and ko
• add ctlptl Kind+registry config plus Tilt/ko dev-loop config
• add Moon dev tasks and downstream docs for the local operator development stack
• document the intended local development flow in AGENTS.md for future agents

Validation

• proto install --quiet
• proto run kind -- version
• proto run ctlptl -- version
• proto run tilt -- version
• proto run ko -- version
• moon run root:chart-validate
• moon run root:generate
• bash -n dev/ko-build.sh dev/stack-smoke.sh
• git diff --check
• moon run root:dev-stack-smoke
• moon run root:dev-down