Build Config from env vars, defaulting any value that is unset or invalid.
If a policy anchor — MATURITY_HORIZON_CARD_MS or VELOCITY_LIMIT_MINOR — is missing in
production, throws a single CONFIG.INVALID fault listing all missing keys at once, so the
program fails at startup rather than one key at a time during requests.
Build Config from env vars, defaulting any value that is unset or invalid.
If a policy anchor — MATURITY_HORIZON_CARD_MS or VELOCITY_LIMIT_MINOR — is missing in production, throws a single CONFIG.INVALID fault listing all missing keys at once, so the program fails at startup rather than one key at a time during requests.