ConstReadonlyDatabaseError: "E_DATABASE"Database connect/query failure.
ReadonlyInvalidArguments: "E_INVALID_ARGS"A flag/argument combination the command can't act on.
ReadonlyNoConfig: "E_NO_CONFIG"No mj.config.cjs (or equivalent) found.
ReadonlyNonInteractive: "E_NON_INTERACTIVE"A needed value was missing and the run wasn't allowed to prompt for it.
ReadonlyNotFound: "E_NOT_FOUND"A referenced entity, directory, or record doesn't exist.
ReadonlyUnknown: "E_UNKNOWN"Anything not yet categorized. Prefer a specific code.
ReadonlyValidationFailed: "E_VALIDATION_FAILED"Input failed the command's own validation pass.
Stable, machine-readable error codes. An agent branches on these; the human-facing
messageis free to be reworded without breaking anyone.Add cases here rather than inventing ad-hoc strings at a call site — the whole point is that the set is enumerable and greppable.