ci: move automation to GitHub Actions

[petergstfsn]

Summary

• move the Cloudflare build into GitHub Actions
• verify pull requests with the web build and a Wrangler dry run
• upload a preview version after pushes to main or a manual run

Verification

• actionlint
• npm run build
• wrangler deploy --dry-run

Review flags

• CI/deploy configuration changed.
• The publish job requires CLOUDFLARE_API_TOKEN and CLOUDFLARE_ACCOUNT_ID in GitHub Actions secrets.
• This PR does not deploy. After merge and a successful GitHub Actions upload, disable the Cloudflare Git integration.

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[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	opentos	73dff15	Commit Preview URL Branch Preview URL	Aug 15 2026, 04:11 AM

[petergstfsn]

Superseded by #11. The replacement preserves the fully passing verification path while scoping Cloudflare credentials to the upload step and restricting manual uploads to main.