add release skill for Claude Code

Automates the v5.x release proposal workflow: worktree creation,
branch-diff to identify commits, cherry-picking, version bump, and
PR creation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: szegedi

.claude/skills/release/SKILL.md

@@ -0,0 +1,105 @@
+---
+name: release
+description: Create a release proposal for the v5.x branch by cherry-picking commits from main
+disable-model-invocation: true
+argument-hint: "[version (optional, auto-determined from PR labels)]"
+---
+
+Create a v5.x release proposal. If a version is provided as $ARGUMENTS, use it. Otherwise, determine it automatically (see step 2).
+
+## Prerequisites
+
+The `branch-diff` tool must be installed globally:
+
+```
+npm install branch-diff -g
+```
+
+## Steps
+
+### 1. Identify commits to cherry-pick
+
+Use the `branch-diff` tool to list commits on `main` not yet applied to `v5.x`:
+
+```
+branch-diff v5.x main
+```
+
+Review the output with the user. Skip:
+- Version bump commits (e.g. "Bump package version on to 6.0.0-pre")
+- Commits that would result in empty cherry-picks (already applied or superseded)
+
+Confirm the list of commits with the user before proceeding.
+
+### 2. Determine the version number
+
+If the user didn't provide a version, determine it from PR labels. For each commit being cherry-picked, extract the PR number from the commit message (e.g. `(#305)`) and check its labels:
+
+```
+gh pr view <number> --json labels --jq '.labels[].name'
+```
+
+- If any PR has a `semver-minor` label, the release is a **minor** bump.
+- If all PRs have at most a `semver-patch` label, the release is a **patch** bump.
+
+Get the current version from the tip of `v5.x` (the most recent version commit message), then compute the next version accordingly. Confirm the version with the user.
+
+In the steps below, `$VERSION` refers to the determined version number.
+
+### 3. Create a worktree
+
+Create a git worktree from the current repo, checking out a new branch `v$VERSION-proposal` based on the `v5.x` branch:
+
+```
+git worktree add ../pprof-nodejs-v5 -b v$VERSION-proposal v5.x
+```
+
+All subsequent steps run in the worktree directory.
+
+### 4. Cherry-pick commits
+
+Cherry-pick the agreed-upon commits in chronological order (oldest first):
+
+```
+git cherry-pick <hash1> <hash2> ...
+```
+
+If a cherry-pick has conflicts, stop and resolve with the user.
+
+### 5. Create the version bump commit
+
+Bump the version in package.json and package-lock.json using npm, then commit:
+
+```
+npm version $VERSION --no-git-tag-version
+git add package.json package-lock.json
+git commit -m "v$VERSION"
+```
+
+### 6. Push and create a PR
+
+Push the branch and create a PR targeting `v5.x`:
+
+```
+git push -u origin v$VERSION-proposal
+```
+
+Create the PR with `gh pr create --base v5.x`. The PR body should categorize the cherry-picked PRs by type, following this pattern:
+
+```markdown
+# New features
+* #NNN
+
+# Improvements
+* #NNN
+
+# Bug fixes
+* #NNN
+
+# Other (build, dev)
+* #NNN
+```
+
+Only include sections that have entries. Reference PR numbers from the original commit messages.
+
+See https://github.com/DataDog/pprof-nodejs/pull/295 for an example.