Module error 

Unified error taxonomy for the CLI handlers + the exit-code contract (criterion G / §F9’s “specific exit codes per error class”).

Exit codes are a durable part of the CLI contract — scripts that branch on them will depend on the numbers below. Add new classes by appending new codes; renumbering is breaking.

Modules

code

Exit code taxonomy. Matches criterion G from the #16 plan.

Enums

CliError

Error sources the CLI dispatcher knows about. The human-readable Display output is what lands on stderr; CliError::exit_code maps variants onto the code table.