pub fn validate_tail(tail: &[String], schema: &Schema) -> Result<(), String>Expand description
Validate the user’s extra argv tail against a schema. Always called
before run::exec_command — the parser’s lenient-unknowns mode is
keyed off schema.strict so choice validation on declared flags
fires regardless, while unknown-flag rejection stays opt-in.
The tokenizer from crate::args::parser is reused so “did you
mean” suggestions, cluster, and equals handling come for free.