Deploy Cf Worker

Upload backend/static/og-prerender.js to Cloudflare Workers.

Reads CLOUDFLARE_API_TOKEN from Railway env vars and uses the CF REST API directly — no wrangler CLI or Node.js required.

Routes (equity-rank.com/*) are NOT modified — they persist from the initial wrangler deploy --env production setup. This endpoint only replaces the script content.

Returns deploy status dict: {ok, worker_name, script_size, deployed_at, account_id} On failure: {ok: False, error: str, details?: str}