14-task TDD plan to replace bind-mount JAR delivery with init-container
download from Cameleer over HTTP, sitting behind a new ArtifactStore
abstraction. Lands withUsernsMode hardening (last open gap from #152) and
gives storage a clean migration path to OCI (Zot) tracked separately in
issue #158.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>