CHW-1403 PaddleNotConfigured

payment processor not configured on this instance; contact support or self-host operator

Default message: payment processor not configured on this instance; contact support or self-host operator
HTTP status: 503 (server)

Problem. /api/billing/checkout or /api/billing/portal returned 503. Cause. The self-hosted instance has no Paddle credentials configured, so paid plan transitions are disabled. Fix. Ask the operator to set the Paddle env vars, or stay on the Free tier. The frontend should hide the upgrade button when Paddle is unconfigured — this is the defensive backstop. HTTP 503.