Add plan-only semantic GC candidate reporting

README.ko.md

@@ -501,6 +501,12 @@ python3 scripts/release_smoke.py
 
 버전별 릴리스 노트는 [CHANGELOG.md](CHANGELOG.md)에 기록하며, 사전 배포 게이트는 플러그인 매니페스트 버전과 일치하는 항목이 있는지 확인합니다.
 
+### 실험적 semantic-GC plan gate
+
+`semantic-gc`는 기본 비활성화된 deny 전용 계획 검토 gate입니다. 기본 비활성화는 registry intent를 뜻하며, 명시적 plan CLI는 계속 실행할 수 있지만 omission이나 runtime action을 활성화하지 않습니다. 전체 envelope나 graph topology가 모호하면 graph evaluation을 억제합니다. 도달할 수 없는 node는 semantic irrelevance의 증명이 아니라 검토 후보일 뿐이며 omission과 runtime action은 승인되지 않습니다. missed-context note는 신뢰되지 않은 입력입니다. 이 planner는 context/artifact 내용을 읽지 않고 provenance, fallback, provider, hosted 절감을 검증하지 않습니다. Exit 0은 `ready_for_plan_review`만 뜻하며 delete/omit 권한이 아닙니다.
+
+context-guard experiments plan semantic-gc --json --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"root","references":[],"is_root":true,"protected_zone":false}' --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"orphan","references":[],"is_root":false,"protected_zone":false,"content_sha256":"bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","provenance":{"source_label":"canonical-example","receipt_id":"0123456789abcdef"},"missed_context_note":"A reviewer could lose the orphaned rationale.","exact_fallback_command":"context-guard-artifact get 0123456789abcdef --full"}' --provider-boundary-ack --human-review-ack --protected-zone-policy deny
+
 ## 라이선스
 
 Copyright 2026 jinhongan. Apache License 2.0으로 배포됩니다. 자세한 내용은 [LICENSE](LICENSE)와 [NOTICE](NOTICE)를 참고하세요.

README.md

@@ -554,6 +554,12 @@ When a helper under `context-guard-kit/` changes, run `python3 scripts/sync_plug
 
 Versioned release notes live in [CHANGELOG.md](CHANGELOG.md); the prepublish gate requires an entry matching the plugin manifest version before publishing.
 
+### Experimental semantic-GC plan gate
+
+`semantic-gc` is a default-off, deny-only, plan-review gate over a caller-declared graph. Default-off describes registry intent; the explicit plan CLI remains invocable and never enables omission or runtime action. Graph evaluation is suppressed when the complete envelope or topology is ambiguous. Unreachable nodes are review candidates, not proof of semantic irrelevance: omission and runtime action remain unauthorized. Candidate missed-context notes are untrusted. The planner does not read context/artifact content or verify provenance, fallback, providers, or hosted savings. Exit 0 means only `ready_for_plan_review`; it is never delete/omit authority.
+
+context-guard experiments plan semantic-gc --json --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"root","references":[],"is_root":true,"protected_zone":false}' --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"orphan","references":[],"is_root":false,"protected_zone":false,"content_sha256":"bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","provenance":{"source_label":"canonical-example","receipt_id":"0123456789abcdef"},"missed_context_note":"A reviewer could lose the orphaned rationale.","exact_fallback_command":"context-guard-artifact get 0123456789abcdef --full"}' --provider-boundary-ack --human-review-ack --protected-zone-policy deny
+
 ## License
 
 Copyright 2026 jinhongan. Licensed under the Apache License 2.0. See [LICENSE](LICENSE) and [NOTICE](NOTICE).

context-guard-kit/README.md

@@ -114,6 +114,11 @@ context-guard experiments plan proof-carrying-context --json --proof-unit-json '
 
 Claude Code에 적용하려면 `settings.example.json`을 `.claude/settings.json`으로 복사하되, 먼저 작은 repo에서 quoting/종료 코드를 확인하세요.
 
+### Experimental semantic-GC plan gate
+
+`semantic-gc` is a default-off, deny-only, plan-review gate over a caller-declared graph. Default-off describes registry intent; the explicit plan CLI remains invocable and never enables omission or runtime action. Graph evaluation is suppressed when the complete envelope or topology is ambiguous. Unreachable nodes are review candidates, not proof of semantic irrelevance: omission and runtime action remain unauthorized. Candidate missed-context notes are untrusted. The planner does not read context/artifact content or verify provenance, fallback, providers, or hosted savings. Exit 0 means only `ready_for_plan_review`; it is never delete/omit authority.
+
+context-guard experiments plan semantic-gc --json --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"root","references":[],"is_root":true,"protected_zone":false}' --context-unit-json '{"schema":"contextguard.semantic-gc-unit.v1","unit_id":"orphan","references":[],"is_root":false,"protected_zone":false,"content_sha256":"bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","provenance":{"source_label":"canonical-example","receipt_id":"0123456789abcdef"},"missed_context_note":"A reviewer could lose the orphaned rationale.","exact_fallback_command":"context-guard-artifact get 0123456789abcdef --full"}' --provider-boundary-ack --human-review-ack --protected-zone-policy deny
 
 ## License