Function strict_mode 

pub fn strict_mode() -> bool

Whether MURK_STRICT is enabled. Strict mode trades convenience for a hard “never let a secret touch the disk” guarantee — see is_ram_backed.

On for 1, true, or yes (case-insensitive). Off when unset, empty, or any other value (including 0). This is the user/session-level strict toggle; vault-declared policy will later flip the same behaviors.