feat: add release-workflow skill

.claude/skills/release-workflow/SKILL.md

@@ -0,0 +1,88 @@
+---
+name: release-workflow
+description: Use when preparing or executing a release for the glean-claude-plugins marketplace. Triggers on "release", "bump version", "publish", "npm run release", "new version", or when the user wants to cut a new plugin version.
+disable-model-invocation: true
+---
+
+# Release Workflow
+
+Follow these steps in order. Do not skip steps.
+
+## Pre-flight checks
+
+**Step 1: Verify all plugin versions are in sync**
+
+Run:
+```bash
+for p in plugins/*/.claude-plugin/plugin.json; do
+  echo "$p: $(node -e "console.log(JSON.parse(require('fs').readFileSync('$p','utf8')).version)")"
+done
+```
+
+All versions must match the current marketplace version in `.claude-plugin/marketplace.json`.
+If any are out of sync, fix them before proceeding and commit the fix separately.
+
+**Step 2: Validate plugin structure**
+
+Run:
+```bash
+node scripts/validate-plugins.mjs
+```
+
+All plugins must pass validation. Fix any errors before proceeding.
+
+**Step 3: Verify working tree is clean**
+
+Run:
+```bash
+git status
+```
+
+Expected: `nothing to commit, working tree clean`
+
+## Run the release
+
+**Step 4: Run release-it**
+
+```bash
+npm run release
+```
+
+This will:
+- Prompt for the next version (patch/minor/major)
+- Update `package.json`, `.claude-plugin/marketplace.json`, and ALL `plugins/*/.claude-plugin/plugin.json` via the bumper
+- Generate/update `CHANGELOG.md` from conventional commits
+- Create a git tag `v<version>`
+- Commit with message `chore: release v<version>`
+
+**Step 5: Post-release verification**
+
+Run:
+```bash
+for p in plugins/*/.claude-plugin/plugin.json; do
+  echo "$p: $(node -e "console.log(JSON.parse(require('fs').readFileSync('$p','utf8')).version)")"
+done
+```
+
+All 10 plugin versions should show the new version number.
+
+**Step 6: Push tag and commits**
+
+```bash
+git push && git push --tags
+```
+
+## Plugins covered by the bumper (bumped automatically)
+
+- `plugins/glean-core`
+- `plugins/glean-search`
+- `plugins/glean-people`
+- `plugins/glean-meetings`
+- `plugins/glean-docs`
+- `plugins/glean-code`
+- `plugins/glean-dev-docs`
+- `plugins/glean-skills`
+- `plugins/glean-productivity`
+- `plugins/glean-project`
+
+**Adding a new plugin?** You MUST add its `plugin.json` path to the `@release-it/bumper` `out` array in `.release-it.json`, or its version will silently drift on the next release.