ci: add docs environment to cloudflare-deploy workflow

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

Author: jaysin586

.github/workflows/cloudflare-deploy.yml

@@ -19,6 +19,7 @@ jobs:
     deploy:
         if: ${{ github.event_name == 'workflow_dispatch' || github.event.pull_request.merged == true }}
         runs-on: blacksmith-2vcpu-ubuntu-2404 # trunk-ignore(actionlint/runner-label)
+        environment: docs
         name: Deploy
         steps:
             - name: Checkout