913d18755e
Iteration stderr-markers-2 close, task 5 of the stderr-class-markers plan. C14's Current state gains the marker paragraph — note/warning classes for continuing-run diagnostics, bare `aura: ` for exit-carrying error lines and plain info lines, grep-stable grammar, single source in aura-cli/src/diag.rs — and the glossary gains the `stderr class marker` entry. No new C-number: C14 already owns the CLI stderr conventions and the exit-code partition this grammar completes (derivation logged on the #278 decision thread). With this the milestone promise is shipped: the two diagnostic classes are machine-separable on stderr (#278), and the all-zero-trade walk-forward announces itself instead of completing silently (#313). Exit-code semantics unchanged throughout. closes #278 closes #313