🔨 add local cleanup skill

Author: Miyamura80

.claude/skills/cleanup/SKILL.md

@@ -0,0 +1,143 @@
+---
+name: cleanup
+description: Git branch hygiene - delete merged/closed branch, prune stale refs, sync dependencies
+user_invocable: true
+triggers:
+  - /cleanup
+---
+
+# Git Cleanup Skill
+
+Automates git branch hygiene after merging or closing PRs. Safely deletes merged branches (and force-deletes closed/abandoned branches), prunes stale remote tracking refs, syncs dependencies, and runs garbage collection.
+
+## Workflow
+
+Execute these steps in order:
+
+### 1. Check current branch
+
+```bash
+git branch --show-current
+```
+
+Store the result as `CURRENT_BRANCH`.
+
+### 2. Guard against main/master
+
+If `CURRENT_BRANCH` is `main` or `master`:
+- Report: "Already on main branch. No branch to clean up."
+- Skip to step 7 (pull latest) and continue from there.
+
+### 3. Check for uncommitted changes
+
+```bash
+git status --porcelain
+```
+
+If output is non-empty:
+- Warn the user: "You have uncommitted changes. Please commit or stash them first."
+- Stop and do not proceed.
+
+### 4. Check if branch is merged or closed
+
+First check for merged PRs:
+```bash
+gh pr list --state merged --head CURRENT_BRANCH --json number
+```
+
+If merged, proceed to step 5.
+
+If not merged, check for closed PRs:
+```bash
+gh pr list --state closed --head CURRENT_BRANCH --json number
+```
+
+If closed (result is non-empty):
+- Report: "Branch 'CURRENT_BRANCH' has a closed (unmerged) PR. Proceeding with deletion."
+- Proceed to step 5 (will use force delete in step 6).
+
+If neither merged nor closed:
+- Check if the branch is merged locally: `git branch --merged main | grep -w CURRENT_BRANCH`
+- If not merged anywhere, warn: "Branch 'CURRENT_BRANCH' does not appear to be merged or closed. Use `git branch -D` manually if you want to force delete."
+- Stop and do not proceed.
+
+Store whether the branch was `MERGED` or `CLOSED` for use in step 6.
+
+### 5. Switch to main
+
+```bash
+git checkout main
+```
+
+### 6. Delete the branch
+
+If branch was `MERGED`:
+```bash
+git branch -d CURRENT_BRANCH
+```
+
+If branch was `CLOSED` (PR closed without merging):
+```bash
+git branch -D CURRENT_BRANCH
+```
+
+Report: "Deleted branch CURRENT_BRANCH." (mention if force-deleted due to closed PR)
+
+### 7. Pull latest
+
+```bash
+git pull origin main
+```
+
+### 8. Prune remote tracking refs
+
+```bash
+git fetch --prune
+```
+
+### 9. Delete stale local branches
+
+Find and delete local branches whose upstream is gone:
+
+```bash
+git for-each-ref --format '%(refname:short) %(upstream:track)' refs/heads | while read branch track; do
+  if [ "$track" = "[gone]" ]; then
+    git branch -d "$branch" 2>/dev/null && echo "Deleted stale branch: $branch"
+  fi
+done
+```
+
+Report any branches deleted.
+
+### 10. Sync dependencies
+
+Detect package manager and sync:
+
+- If `uv.lock` exists: `uv sync`
+- Else if `bun.lockb` exists: `bun install`
+- Else if `package-lock.json` exists: `npm install`
+- Else if `requirements.txt` exists: `pip install -r requirements.txt`
+- Else: Skip dependency sync
+
+### 11. Git garbage collection
+
+```bash
+git gc --prune=now
+```
+
+### 12. Summary
+
+Report completion:
+- Branch deleted (if applicable)
+- Number of stale branches pruned
+- Dependencies synced (which package manager)
+- Garbage collection complete
+
+## Error Handling
+
+- **Dirty working tree**: Stop immediately and ask user to commit/stash
+- **Branch not merged or closed**: Warn and stop - never force delete without explicit user request
+- **Branch closed (not merged)**: Force delete with `-D` since branch is abandoned
+- **Already on main**: Skip branch deletion, continue with pull/prune/gc
+- **No remote**: If `git pull` fails due to no remote, continue with local operations
+- **gh CLI not available**: Fall back to `git branch --merged` check