Update vibe-test target refs from xds to astryx
Night-Watch-Designer: target lists (astryx, baseline, html) and the
screenshot filename example (screenshot-dd-2-astryx.png) now match the
vibe-test pipeline, which uses the 'astryx' target. Vibe-Evaluation: the
Astryx+Tailwind skill-doc path is now .generated/astryx-tailwind-skill.md.
Non-vibe references (the 'xds' sandbox node name, repo paths, and Night
Watch state files) are intentionally left unchanged.