Tobiishi Drop

Purpose

Set down a change unit that will not be finished, and say where that leaves the journey. A 飛び石 Tobiishi ends one of two ways: it is sealed (tobiishi-seal, which merges the work) or it is dropped (this skill, which merges nothing). A dropped unit keeps its whole folder, at journey/tobiishi/drop/<key>/, and every branch it had stays where it was, unmerged, so nothing the change made is lost and nothing it made reaches main.

The script decides and moves; this file sequences it and commits. scripts/drop.py refuses what may not be dropped, moves the folder, marks the context and removes the worktrees. Whatever it refuses, this skill does not work around.

The station and the seed are not touched. Dropping the unit leaves its station open and its seed's checklist as it was. Whether to open the next station, or to retire a walked seed, is another seat's call and is named at the end, never performed here.

Shared mechanics. How a journey artifact changes folder and how that commit is built is <CORE>/docs/journey_move.md and <CORE>/doctrine/governance/commit_via_builder.md. Read them; this file names the section it leans on at each step and restates none of it.

Posture

PM only. Run in a pm: session or as the pm subagent. Invoked from anywhere else, halt at once, change nothing, say the posture is wrong, and name both ways in: open a pm: session, or launch the pm subagent. The seat's contract is <CORE>/roles/loaders/pm_global.md. Whether a unit is dropped is the PM's judgment, and shukuba-refine is where the PM makes it and runs this skill — the owner's ruling of 2026-09-19. The gate is there because the run moves, commits and removes worktrees with nobody answering — <CORE>/doctrine/setup/authoring_layers.md § A skill that acts unattended gates to its seat. No other seat may run this skill.

Input

Three values, all required: the project, the change key (<YYYY-MM-DD>_<slug>, the folder name under journey/tobiishi/) and the reason. If any is missing, or the reason is blank, halt and name what is missing. Never compose the reason from the unit's files or the conversation, and never give it a default: it is the commit's record of why work was set down, and only the caller knows it.

Workflow

Run from the instance root. <drop> is python3 <CORE>/../skills/pm/.claude/skills/tobiishi-drop/scripts/drop.py --root ..

Step 1 — Check, before anything changes

<drop> check <project> <key> "<reason>"

Exit 1 is a refusal: blank reason, a key that is sealed, already dropped or no open unit, or a worktree with uncommitted work, each named. Stop at the first refusal — print it, change nothing, and do not retry with different values. The script checks every worktree before any effect, so one dirty worktree stops the whole drop; committing or discarding that work is the owner's call, not this skill's. On success it lists each worktree close will remove.

Step 2 — Move the unit and mark the context

<drop> apply <project> <key>

It git mvs the folder to tobiishi/drop/<key>/, creating drop/ on the first drop. It prints every path the commit must declare, then a last line saying whether CONTEXT_PM.md was marked. Keep the printed paths, and whether the context was marked.

Step 3 — Commit on main

Per <CORE>/docs/journey_move.md § The commit and <CORE>/doctrine/governance/commit_via_builder.md, through <CORE>/tools/commit_builder.py with --repo .:

• The move is already staged, so declare it with --staged, naming both halves of every path apply printed. CONTEXT_PM.md rides --add only when apply said it was marked — adding it otherwise says something false about the commit.
• Subject drop: <key>. Body the reason, verbatim. When the reason holds a backtick, pass it through a file rather than the command line.
• --actor pm, and no --skill. A move commits nothing a skill produced.
• --directional is Shukuba: <open station> — aside: dropped <key> when a station is open at the project's journey/shukuba/ root, else Agari: <project> — aside: dropped <key>. A drop sets work down, and a set-down reads aside:, never progress:.

Then eyeball git show --stat: one rename per file of the unit, plus CONTEXT_PM.md only when marked.

Step 4 — Close the worktrees

<drop> close <project> <key>

Only after the commit. It removes each worktree without --force and never deletes a branch. A failure here leaves a dropped unit with a live worktree, which is safe and is reported as it is. Its output is the report: the key and its new path, the worktrees closed and branches kept, the context mark, and where the journey stands.

Step 5 — Say which pointers the move broke

python3 "<CORE>/tools/check_journey_links.py" --repo .

Report whatever it names, per <CORE>/docs/journey_move.md § After the move, say which pointers it broke. Do not gate on its exit code: a drop that refuses because some other file points at the wrong place is stricter than the journey wants.

Step 6 — Report

Print what close printed, in its order, then state the next owner, and only state it:

• The station is still open. Whether it still has work, or is reached, is the route's to say — shukuba-refine's when it ran this skill.
• Where no unchecked item remains on the seed, the retire is owed to the Scrum Master (nemawashi-retire).

This run parks, ticks, opens and retires nothing, and does not offer to.

---

Outputs

Effect	Produced when
tobiishi/<key>/ moved to tobiishi/drop/<key>/, plus CONTEXT_PM.md marked when it names the unit, in one commit on main	Success (Steps 2-3)
Worktrees removed, branches kept	Success (Step 4)
A report of where the journey stands, and the pointers the move broke	Always after a commit
No change; the refusal printed	Any refusal (Step 1), or a wrong posture

Critical Rules

• PM only. Any other posture halts before a single call, with the way in named.
• No default reason, no composed reason. A missing or blank reason halts.
• Check, then commit, then close. Every refusal comes before any effect, and the record on main comes before the teardown, so a failed teardown never leaves a removed worktree for a drop that did not commit.
• A branch is never deleted and a worktree is never force-removed. This is where a drop departs from the seal, which merges and deletes. A drop merges nothing.
• Nothing else moves. Never edit anything under journey/shukuba/, journey/nemawashi/ or <CORE>/../skills/pm/.claude/skills/tobiishi-seal/. A sealed or already dropped unit is refused, never re-dropped.
• Don't offer the next move. Name its owner and stop.