refactor(ui): finish Astryx component convergence

[Astro-Han]

Summary

• make Astryx the sole generic component foundation across packages/ui and the desktop renderer
• migrate active Base UI consumers and Maka compatibility primitives to Astryx Button, Banner, EmptyState, Item, Kbd, Spinner, Table, and Collapsible APIs
• delete retired wrappers, stories, tests, legacy component chrome, the Base UI dependency, and its generated license notice
• add behavior and governance contracts for component authority, row-header semantics, live-region ownership, keyboard names, and fail-closed visual scopes

Refs #1565. Tailwind and build-infrastructure removal remain a separate final slice.

Verification

• npm run build
• npm test --workspace @maka/ui (278 passed)
• desktop compiled test suite (1821 passed); the workspace pretest is currently blocked by main's unchanged packages/runtime-host/src/server/host-kernel.ts console allowlist finding
• npm run lint
• npm run typecheck
• npm run format:check
• node scripts/check-dead-css.mjs --check
• npm run check:third-party-notices
• node scripts/check-visual-contract.mjs --against main --scopes scripts/visual-contract-scopes/issue-1565-final-convergence.json (20 comparisons clean; declared changes remain under bounded scopes)
• npm run check:hit-test (5 representative routes clean)
• npm --workspace @maka/desktop run build-storybook and Storybook smoke (51 checks)
• npm ls @base-ui/react --all (empty)