fix(release): use the pinned public engine root

[rldyourmnd]

Summary

• resolve release-critical implementation paths through the existing split-aware engine layout
• retain the control-plane role gate while binding source proof to modules/github-device-sync
• cover monolithic and private-estate/public-engine layouts

Root cause

After the public/private split, release operations required a control-plane anchor but looked for core/releaseconsumer under the private estate root. Running from the public module found the code but correctly failed the control-plane role gate.

Verification

• go test ./core/app ./core/releaseconsumer
• scripts/validate_go_core.sh --quick
• git diff --check