CAMELEER_SERVER_RUNTIME_BASEIMAGE was never set on provisioned
per-tenant server containers, causing them to fall back to the
server's hardcoded default. Added CAMELEER_SAAS_PROVISIONING_RUNTIMEBASEIMAGE
as a configurable property that gets forwarded during provisioning.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>