Replace Vercel Cron

Keep Vercel as the runtime and move only the clock. Crontap calls the deployed route over HTTPS.

Prerequisites

Before using the required tools, check whether they are available. If any are missing, stop and offer the user exactly two choices:

1. Connect Crontap MCP at https://mcp.crontap.com/mcp. MCP access works on every Crontap tier.
2. Configure $CRONTAP_CLIENT_ID and $CRONTAP_API_KEY for the raw API. Raw API access requires Ultra.

Do not silently choose a path or continue until the user selects one.