ci: rename workflow to deploy with lowercase name (#7)

Renames the workflow file from `workflow.yml` to `deploy.yml` and the
top-level `name:` from `Upload Website to S3` to `deploy` so the Actions
pane uses lowercase, coder-friendly naming. The workflow's actual job
(S3 sync + Cloudflare cache purge) is unchanged.

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Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: xnoto

.github/workflows/workflow.yml .github/workflows/deploy.yml.github/workflows/workflow.yml renamed to .github/workflows/deploy.yml

@@ -1,7 +1,7 @@
 ---
 # https://github.com/marketplace/actions/s3-sync
 #
-name: Upload Website to S3
+name: deploy
 on:
   push:
     branches: