HsuanYuLee Checkpoint
checkpoint 保存、恢復、列出長 session 的工作狀態，讓 context compression 或換 session
後能接回 branch、ticket、phase、next action。
Contract
Checkpoint 是 session continuity tool，不是 planning、triage、或 implementation skill。 它只寫 workspace memory / timeline 類的 local state，不替下游 skill 決定 scope，也不自動切 branch。
Mode Routing
| User says | Mode | Reference |
|---|---|---|
checkpoint, 存檔, save checkpoint, save state |
save | checkpoint-save-flow.md |
resume, 恢復, resume checkpoint, 接回去 |
resume | checkpoint-resume-list-flow.md |
list checkpoints, 列出存檔, show checkpoints |
list | checkpoint-resume-list-flow.md |
Ambiguous input defaults to save.
Reference Loading
| Situation | Load |
|---|---|
| Any run | polaris-project-dir.md, session-timeline.md |
| Save | checkpoint-save-flow.md, checkpoint-carry-forward-flow.md |
| Resume / list | checkpoint-resume-list-flow.md |
Hard Rules
- Save must capture branch, git status summary, ticket, todo disposition, phase, next action, and recent timeline context.
- 回報 checkpoint saved 前，carry-forward validation 必須通過。
- Resume verifies the checkpoint branch exists before suggesting a switch.
- 未取得使用者明確指示前，不切 branch、不 stash、不 rewrite memory。
- 不可默默丟掉 pending items；每項都要標記 done、carry-forward、或 dropped。
Completion
Save 回傳 branch、ticket、phase、next action、resume phrase。Resume 回傳 checkpoint timestamp、branch、ticket、可取得時的 current status、next action。List 回傳 recent checkpoint rows。
Step 2.5 — L2 Deterministic Check: cross-session-carry-forward
Save mode 的 carry-forward gate 由 checkpoint-carry-forward-flow.md 執行；必須呼叫
.claude/skills/checkpoint/scripts/check-carry-forward.sh，通過後才可回報 checkpoint saved。