ci: add workflow to publish OpenClaw skills to ClawHub (#55)

* ci: add workflow to publish OpenClaw skills to ClawHub

* ci: use documented clawhub sync flags

* ci: harden publish-skills workflow

- Pin clawhub@0.7.0 for supply-chain safety
- Add concurrency group to prevent parallel publishes
- Add PR dry-run validation
- Guard against missing CLAWHUB_TOKEN secret
- Add changeset file

---------

Co-authored-by: jpoehnelt-bot <jpoehnelt-bot@users.noreply.github.com>

.changeset/publish-skills-workflow.md

@@ -0,0 +1,5 @@
+---
+"@googleworkspace/cli": patch
+---
+
+Add workflow to publish OpenClaw skills to ClawHub

.github/workflows/publish-skills.yml

@@ -0,0 +1,47 @@
+name: Publish OpenClaw Skills
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "skills/**"
+      - ".github/workflows/publish-skills.yml"
+  pull_request:
+    branches: [main]
+    paths:
+      - "skills/**"
+      - ".github/workflows/publish-skills.yml"
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: false
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Install ClawHub CLI
+        run: npm i -g clawhub@0.7.0
+
+      - name: Publish skills
+        env:
+          CLAWHUB_TOKEN: ${{ secrets.CLAWHUB_TOKEN }}
+        run: |
+          if [ -z "$CLAWHUB_TOKEN" ]; then
+            echo "::error::CLAWHUB_TOKEN secret is not set"
+            exit 1
+          fi
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            clawhub sync --root skills --all --dry-run
+          else
+            clawhub sync --root skills --all
+          fi