fix(kvb-cleanup): hand sandbox worktree removal to the operator

An agent sandbox mounts every .git/worktrees/<id> read-only, so git worktree remove unregisters the worktree and then fails with EBUSY; container-owned files fail with EACCES. The worktree rules now forbid removal inside the sandbox and hand the operator the ownership count, chown and removal command in one message. A dirty worktree is a candidate only when all its changed and untracked content is preserved at a branch tip, and an untagged image with RepoDigests counts as a medium-risk digest pull. Both files were trimmed so the skill text does not grow.

🎯 Fix: 92 %
💥 Break: 2 %
💸 Cost: 100 %
⏱️ Time: 100 %
🛡️ Security: 100 %
🏆 Score: 90
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

skills/kvb-cleanup/docker.md

@@ -2,31 +2,25 @@
 
 ## Inventory
 
-`docker system df -v`; containers with state and compose project label,
+`docker system df -v`: containers with state and compose project, volumes
-volumes with the containers using them (`docker ps -a --filter
+with their users (`docker ps -a --filter volume=<name>`), dangling and unused
-volume=<name>`), dangling and unused images, build cache, unused networks.
+images, build cache, unused networks. An untagged image with `RepoDigests`
-For every stopped container (`exited`, `created`) record its volumes
+is a digest-pinned pull: medium. Per stopped container its volumes
-(`{{.Mounts}}`); for every volume no running container uses, record size,
+(`{{.Mounts}}`); per volume without a running user its size, `CreatedAt` and
-`CreatedAt` (`docker volume inspect`) and compose project label, anonymous
+compose project, anonymous ones included.
-ones included.
 
 ## Volumes checklist
 
-Stopped containers and volumes always get their own checklist
+Stopped containers and volumes get their own checklist (`multiSelect: true`,
-(`multiSelect: true`, header `⚠ Volumes`, in a further call when call 1 is
+header `⚠ Volumes`, a further call when call 1 is full), each one unless a
-full). Every stopped container and every volume without a running container
+peer claimed it, `unknown` and anonymous ones included. Question text:
-appears there unless a peer claimed it; none is dropped as "not proposed",
-`unknown` and anonymous ones included. The question text carries the warning:
 `Deleting a volume is irreversible; its data does not come back unless the
-description says how.` One option per stopped container together with its
+description says how.` One option per stopped container with its volumes,
-volumes (removing the container alone frees nothing of them), one per
+one per unattached volume, anonymous ones grouped; each names size,
-unattached volume, anonymous ones grouped. Each description gives size,
+`CreatedAt`, owner or project, and what is lost.
-`CreatedAt`, owner or compose project, and what is lost.
 
 ## After removing images
 
-Locally built images free little on their own: their layers stay behind as
+Built images leave their layers as build cache: re-measure `docker system
-build cache. Re-measure `docker system df`; the layers show up as reclaimable
+df`, then offer `docker builder prune --filter until=24h`, after asking the
-build cache. Offer `docker builder prune --filter until=24h` as a follow-up
+peers that claimed build cache, outside their builds.
-candidate, ask the peers that claimed build cache first, and run it outside
-their running builds.

skills/kvb-cleanup/worktrees.md

@@ -2,20 +2,25 @@
 
 ## Inventory
 
-Per worktree: size (`du -sh`), dirty state (`git status --short`), whether
+Per worktree: size (`du -sh`), dirty state, whether its branch is pushed and
-its branch is pushed, and whether its HEAD is already contained in an
+whether its HEAD is in an integration line (the default branch and every
-integration line: the default branch and every branch the project merges
+branch the project merges features into; ask the operator or the project's
-features into (ask the operator or the project's memory which ones). With
+memory). With `pkgmgr`, `pkgmgr branch gc --json --sizes --merged-into
-`pkgmgr` installed, `pkgmgr branch gc --json --sizes --merged-into <line>`
+<line>` (one per line) measures it all; merged-clean items go to the
-(one per line) measures all of it; its merged-clean items go to the
 `kvb-git-branch-gc` skill.
 
-A clean worktree whose HEAD is in an integration line is medium risk: its
+Clean and in a line: medium, its ignored files (`node_modules`, build output,
-ignored files (`node_modules`, build output, evidence) are lost, no commit.
+evidence) are lost. Dirty: a candidate only when every changed, staged and
+untracked file is a blob at some branch tip and a detached HEAD is reachable
+from another ref; else it is unique work and stays.
 
 ## Removal
 
-Remove a worktree the way it was made: a slot worktree through the project's
+The way it was made: a slot worktree through the project's teardown target
-teardown target (e.g. `make worktree-down`), run outside the sandbox; a plain
+(e.g. `make worktree-down`), a sidetree through `git worktree remove`,
-sidetree through `git worktree remove` without `--force`, which refuses a
+`--force` only for a dirty one cleared above. Never in an agent sandbox: its
-dirty tree.
+read-only `.git/worktrees/<id>` mounts make git unregister and then fail with
+`Device or resource busy`, container-owned files with `Permission denied`.
+Hand the operator in one message, per worktree, its count of `find <wt> -not
+-user "$USER" -prune | wc -l`, `sudo chown -R "$USER": <wt>` where it is not
+0, then the removal command.