Release v0.2.9 — scaffold packaging fix for v0.2.8

The v0.2.8 scaffold tag was published with stale bundled vendor due
to Packagist's CDN serving cached p2 metadata when composer update
ran during release. Packagist's tag-to-commit cache then refused to
re-evaluate the v0.2.8 tag even after the force-update at GitHub.

v0.2.9 is the same code as the intended v0.2.8 (vendor at framework
v0.2.8) but with a fresh tag Packagist will properly index. Framework
itself remains at v0.2.8 — scaffold composer.json still pins ^0.2.8
which resolves to the v0.2.8 framework release.

Future composer create-project should use v0.2.9 (which composer picks
as latest automatically via caret).