refactor: remove legacy UI lint and LOC debt

[JJLiebig]

Remove the legacy function/complexity suppressions and all seven LOC budgets by splitting existing control logic, chart rendering, navigation, playground examples, and browser scenarios into focused modules. Public component imports, behavior, and appearance are preserved; two settings switches and the confidence slider now have accessible names.

The existing package qualification now imports the affected public controls from an isolated packed consumer, covering the new internal ESM module boundaries. All source files are within 600 lines, tests within 900, functions within 100, and complexity within 12. Accessibility exceptions remain limited to documented SVG, forwarded-label, and scroll/pointer semantics.

Validation:

• just check passed: formatting, Oxlint, ESLint, supply-chain watchlist, LOC, TypeScript, and packed-consumer qualification.
• just test-integration: all 19 existing Playwright scenarios passed, including 320/390/768/1440px coverage.
• Original/refactored comparisons matched 1,431 line-item chart states, 726 navigation/playground states, 24 playground actions, and 17 schedule wheel cases.

Fast review rvw_a56598d7 completed with two Astra medium reviewers reporting no findings. CI passed at 69bdcf91a73c6abcc9179754fd0c0bbd235cb16b: https://github.com/nextidemedia/ui/actions/runs/34172557164. No remaining validation gates.