Covers the composer surface: the control row in full and compact forms, preset loading with its new-session flag and the fall-back to a build run when the box empties, carried drafts landing in the launcher's editor (and only there), honest option labels and disabled reasons, Start blocked while the target device is offline, and the in-session gear — gone during a live run, Resume-only after the end.

## Before writing SPEC.md files

Read https://raw.githubusercontent.com/brillout/sdd/refs/heads/main/sdd.md
