docs(cleanup): inventory worktrees by size and integration line

kvb-cleanup asks every peer to report and remove its own unused worktrees and volumes, inventories each worktree's size, dirty state, push state and whether its HEAD is already in an integration line, ranks such clean worktrees as medium risk, and removes slot worktrees through the teardown target and sidetrees through git worktree remove without --force. kvb-git-branch-gc runs its dry run with pkgmgr branch gc --sizes --min-age 24 --merged-into <line> and shows Merged into and Size.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

skills/kvb-cleanup/SKILL.md

@@ -36,6 +36,10 @@ need, one item per line:
 - containers, compose or stack projects, volumes, images, networks
 - running jobs (deploys, tests, builds) and when they finish
 Reply "nothing" if you need none of it. Items you do not answer for stay.
+Also search your own worktrees and volumes for unused ones (branch merged or
+pushed, no uncommitted changes, stack not needed), list them with their size
+as deletion candidates, delete only your own finished items, and tell me what
+you removed.
 ```
 
 ## Step 2: inventory
@@ -56,10 +60,15 @@ Read-only, in parallel, sizes included:
   record its volumes (`{{.Mounts}}`); for every volume no running container
   uses, record size, `CreatedAt` (`docker volume inspect`) and compose project
   label, anonymous ones included.
+- **Worktrees**: per worktree its size (`du -sh`), its dirty state (`git
+  status --short`), whether its branch is pushed, and whether its HEAD is
+  already contained in an integration line: the default branch and every
+  branch the project merges features into (ask the operator or the project's
+  memory which ones). With `pkgmgr` installed, `pkgmgr branch gc --json
+  --sizes --merged-into <line>` (one per line) measures all of it; its
+  merged-clean items go to the `kvb-git-branch-gc` skill.
 - **Other agent dirs**: package and tool caches (pip, npm, pre-commit, act,
-  gh, buildx), worktrees with `git status --short` and whether their branch is
-  merged or pushed, Ansible and build temp dirs. With `pkgmgr` installed,
-  merged branches and worktrees go to the `kvb-git-branch-gc` skill instead.
+  gh, buildx), Ansible and build temp dirs.
 - **Register**: `rasci.py artifacts` of the `kvb-org-artefacts` skill:
   workdir, branch and artifacts of every task in the `kvb-org-rasci` register,
   with its status and worker; `--ended` narrows it to the candidates.
@@ -97,7 +106,7 @@ worktree or compose project name, a container label, an open handle, or
 | Risk | Meaning | Typical items |
 | ---- | ------- | ------------- |
 | low | regenerated automatically, cheap | stopped containers without volumes, dangling images, unused networks, scratch dirs and logs of finished sessions |
-| medium | regenerated, but slow, rate-limited or network-bound | unused tagged images (re-pull, registry limits), build cache (cold rebuilds), package caches |
+| medium | regenerated, but slow, rate-limited or network-bound | unused tagged images (re-pull, registry limits), build cache (cold rebuilds), package caches, clean worktrees whose HEAD is already in an integration line (ignored files such as `node_modules`, build output or evidence are lost, no commit) |
 | high | data loss or a broken run possible | volumes, stopped containers with volumes, running unclaimed containers or stacks, worktrees with uncommitted or unpushed work, unread reports, anything `unknown` |
 
 ## Step 4: propose
@@ -162,6 +171,10 @@ ticked items. Revise repeats call 1; nothing is deleted before `Execute`.
   lets only its owner end it.
 - Idle running stacks go down through the project's teardown target, never by
   removing their containers or volumes underneath them.
+- Remove a worktree the way it was made: a slot worktree through the
+  project's teardown target (e.g. `make worktree-down`), run outside the
+  sandbox; a plain sidetree through `git worktree remove` without `--force`,
+  which refuses a dirty tree.
 - Archive-first items: copy out, verify the copy, then delete.
 - Drop every deleted item from its task as the `kvb-org-artefacts` skill
   says (`set <task> --drop-artifact <kind>:<ref>`), so `artifacts` stays true.

skills/kvb-git-branch-gc/SKILL.md

@@ -23,8 +23,12 @@ and nothing is removed before the operator's pick in this run.
 
 ## Step 1: dry run
 
-`pkgmgr branch gc --json`, with `--all` only when the operator asked for every
-repository, output to `/tmp/branch-gc-<N>.json`. No `git fetch` of your own
+`pkgmgr branch gc --json --sizes --min-age 24 --merged-into <line>`, one
+`--merged-into` per integration line the project merges features into
+(default branch excluded, it always counts), with `--all` only when the
+operator asked for every repository, output to `/tmp/branch-gc-<N>.json`. A
+line is protected, and a checkout at its tip stays as fresh work; an item
+merged into a line names it in `merged_into`. No `git fetch` of your own
 before it: gc fetches without auto-maintenance, while a plain fetch on git
 2.50 or later may prune the sandbox's bind-mount stubs. Every repository's
 `warnings` (a failed fetch) go to the top of the plan. Sort the items:
@@ -53,7 +57,7 @@ silence is not consent.
 
 One table:
 
-| Repo | Branch or worktree | Merged by | Actions | Note |
+| Repo | Branch or worktree | Merged into | Size | Actions | Note |
 
 Then ask with `AskUserQuestion`: