- EnterPlanModeTool: switch to read-only mode with plan file path management - ExitPlanModeTool: restore permissions and validate plan content - PermissionRuleEngine: plan file edit exception in PLAN mode - SystemPromptBuilder: 5-phase plan workflow instructions injection - /plan command: toggle plan mode from command line - Plan file stored at ~/.claude/projects/[path]/PLAN.md Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>