cmux-backendlisted

# cmux Backend Use this skill for backend TypeScript, Cloud VM, provider, database, auth, rate-limit, retry, timeout, or telemetry work. ## Core rules - Default backend TypeScript to Effect under `web/app/api/**`, `web/services/**`, and backend scripts that touch providers, databases, auth, rate limits, retries, timeouts, or telemetry. - Keep Next route handlers thin: parse the request, run one Effect program at the boundary, map typed errors to HTTP responses, and treat unexpected defects separately. - Use plain TypeScript only for trivial data shapes, constants, config files, frontend React code, or small glue where Effect would add ceremony without improving failure handling. - Cloud VM backend logic must stay in Vercel route handlers and Effect services backed by Postgres. - Do not reintroduce Rivet or a raw actor protocol for Cloud VM unless a later architecture doc explicitly changes the control plane. - Production and staging Cloud VM Postgres use the Vercel Marketplace AWS Aurora PostgreSQL OIDC/RDS IAM path. - Runtime env names are `CMUX_DB_DRIVER=aws-rds-iam`, `AWS_ROLE_ARN`, `AWS_REGION`, `PGHOST`, `PGPORT`, `PGUSER`, and `PGDATABASE`. - Run production/staging migrations with `bun db:migrate:aws-rds-iam`; never run Drizzle migrations from Vercel build or route startup. - Local development keeps using the `CMUX_PORT`-derived Docker Postgres path from `bun dev`. - Cloud VM create pricing gates should use Stack Auth team payment items when enabled. - Postgres remai