[codex] Add Hermes context poisoning scanner

[RedBeret]

Summary

• add components/hermes/hermes-context-scan, a content-free scanner for memory/context poisoning phrases
• report only path, line number, and reason; do not print private memory contents
• add an allowlist example, installer, component docs, and smoke coverage
• include the component in isolated setup testing and public docs

Validation

• bash scripts/smoke-test.sh
• bash components/hermes/hermes-context-scan/context-scan.sh ~/.hermes -> pass after narrowing default targets to memory/context locations
• bash scripts/publish-check.sh -> passed with existing advisory warnings for historical author review and missing local dependency audit tool