fix(update): guard kit materialization behind ccsk-project detection
ccsk update no longer scatters kit files into arbitrary directories. The global CLI self-update still runs everywhere, but kit templates + agents/skills + plugin are re-materialized only in an existing ccsk project (a dir with .ccsk/ or materialized .claude/skills/ccsk-*), or when you opt in with --force or an explicit --path <dir>.
- Drop commander's
.default on--pathso an explicit--path .reads as deliberate intent. - Add
--forceto override the guard for the current directory. isCcskProject()detection (directory check, not bare existence).