Gates: POS-coverage (CI) + full-app boot smoke — prevent the folk-class outage

The folk outage (missing app/world.js POS -> boot-time relaxation crashed the renderer) shipped green because the star-cruise tests stub app/main.js. Two gates:

• Docs: NEXT.md ship-law (POS-completeness outage law + full-boot in the battery); ADDING-A-GENRE.md (missing POS now noted as CRASHES, not just invisible).

Verified: pos-coverage.js (plain node, CI-safe, wired into verify.sh as `poscover`): every GenreKernel.GENRES key MUST have an app/world.js POS entry, else FAIL.

▶ Play it: Kettle Eschaton — parked on the genre this change names https://stellate.app/?genre=folk&seed=6716&path=1854.5710,1873.5743,1835.5743&xdur=13.122

874a9fb https://github.com/aboard-io/stellate/commit/874a9fbc49a528ddae3576e44c8dfeb76d5c2dbb