T6-T8: web dashboard spec-list (§V10, I.web, I.db)

- dashboard.py: Flask read-only, paged 50/page, ORDER BY staked DESC
- templates/index.html + static/style.css: DESIGN.md Bugatti austere tokens
- test_dashboard.py: oracle (ordering, paging, read-only)
- DESIGN.md style guide (was untracked)

requirements.txt

@@ -1 +1,2 @@
 requests>=2.31
+flask>=3.0