A shared art bible for Habitat assets

Can new assets feel like parts of one world? Added docs/asset-art-bible.md and the local docs/asset-design-board.html, plus the personal habitat-asset-direction skill with automatic discovery. The skill requires actual reference inspection, a concrete asset brief, visual comparison and separate technical verification. It preserves the approved hut as an individual anchor without promoting tree studies, Tomodachi concepts or the generated shrub into a final global style. Measured 16 October 2026 against art-board-37b10107158be159: 6/6 reference images loaded in Chromium 151; 8 displayed source swatches match art/build_assets.py; zero horizontal overflow at viewport widths 1280 and 390 px. Skill quick_validate.py passed using an isolated PyYAML runtime. Desktop/mobile renders are local document evidence, not Unity gameplay or new asset acceptance. Each staged image and sidecar was inspected and individually privacy approved. No paid generation occurred. The next art decision is foliage detail and palette; a separate task owns website integration.