The design check and docs/DESIGN.md stop parking pulls: the red says exactly what to change, and DESIGN.md is no longer one file every pull edits #4063

Probe 2026-10-21 07:15Z (main green on 44f94c4a): in the last ~25 min 11 pull checks failed the same test, design check: nothing added outside the system (#26…), and 7 pulls could not merge because of conflicts in docs/DESIGN.md; 10 pulls were parked in 20 min, mostly for these.

Done:

1. The design check's failure names the file:line, the offending class/colour/size, and the system token or component to use instead ("use var(--space-3) / .card"), so a builder fixes it in one pass; the crew brief tells builders to run it locally before pushing.
2. docs/DESIGN.md stops being a hot file: generated sections (token tables, component lists) are generated from the source by a script and not hand-edited; prose changes go to per-area files under docs/design/ (one per component area), so parallel pulls touch different files.
3. A failing design check on a pull is not a park strike when main changed the rule under it (rule tightened after the pull opened) — re-check on the new rule first.

Test: a fixture pull adding an off-system colour gets a red naming the token to use; two pulls documenting different components never conflict.