ci: add CI workflow and gate deployments on CI success

- Add ci.yml with lint, test, and typecheck jobs
- Update workers.yml to trigger on CI workflow completion
- Update sync.yml to trigger on CI workflow completion
- Update image.yml to trigger on CI workflow completion
- Fix pages-eo.yml secret name to match README (EDGEONE_PAGES_API_TOKEN)

Deployment workflows now only run after CI passes, preventing
broken code from being deployed to any platform.

.github/workflows/pages-eo.yml

@@ -34,4 +34,4 @@ jobs:
           node-version: "22.11.0"
 
       - name: Deploy to EdgeOne Pages
-        run: npx edgeone pages deploy . -n xget6 -t ${{ secrets.EDGEONE_API_TOKEN }}
+        run: npx edgeone pages deploy . -n xget6 -t ${{ secrets.EDGEONE_PAGES_API_TOKEN }}