Function strict_mode 

pub fn strict_mode() -> bool

The effective strict setting: strict is ON when either the operator set a truthy MURK_STRICT or this is an agent_context (MURK_AGENT). There is deliberately no way to turn strict OFF from inside an agent context — an operator who wants convenience simply doesn’t opt into agent context. Strict mode trades convenience for a safer default: don’t write a secret to disk (see is_ram_backed) and don’t fall back to the operator’s stored key (see env::resolve_key_with_source). This is the toggle the strict gates read.