Fix CI build: migrate @fluentui/web-components from v2 API to v3

[Copilot]

Dependabot bumped @fluentui/web-components to v3.0.2, which dropped the v1/v2 registration API (fluentButton(), provideFluentDesignSystem(), etc.), causing 9 TypeScript compile errors in the webpack build.

Changes

• tsconfig.json: moduleResolution: "node" → "bundler" — required for TypeScript to resolve v3's package exports map sub-paths (e.g. @fluentui/web-components/button.js)

• src/Scripts/ui/mha.ts and src/Scripts/ui/uiToggle.ts: Replace v2 FAST design system registration pattern with v3 side-effect imports:

  // Before (v2 API — no longer exported)
  import { fluentButton, fluentCheckbox, provideFluentDesignSystem } from "@fluentui/web-components";
  provideFluentDesignSystem().register(fluentButton(), fluentCheckbox(), ...);
  
  // After (v3 API)
  import "@fluentui/web-components/button.js";
  import "@fluentui/web-components/checkbox.js";
  // ...

  fluentToolbar is not imported — it was removed from v3 entirely.