Updates - #2

Overview

Modernizes sorting-viewer to a healthy, maintainable state: every dependency
updated to its latest supported major, a full linting/formatting/testing/CI
setup, and a PrimeVue 3 → 4 theming rewrite. Bumps the app to 1.0.0.

Each commit is self-contained and passes the full local gate
(lint → format:check → type-check → test:run → build).

Highlights

Build stack

• Vue 3.2 → 3.5, Vite 4 → 8, @vitejs/plugin-vue → 6, vue-tsc → 3,
  @vue/tsconfig → 0.9, @types/node → 24, primeicons → 8.
• Replaced the unmaintained npm-run-all with npm-run-all2 and removed the
  unused @vitejs/plugin-vue-jsx.
• Pinned TypeScript to the latest 5.x (5.9) rather than 7 — the native TS 7
  rewrite is not yet supported by typescript-eslint or vue-tsc.

PrimeVue 3 → 4 (the centerpiece)

• Moved to styled-mode theming with the Aura preset.
• Dark mode is now a .dark class toggle via darkModeSelector, replacing the
  old document.styleSheets mutation hack (src/utils/helpers.ts, deleted).
• Renamed the Dropdown component to Select (v4 rename).
• Migrated the design-token CSS variables to their v4 (--p-*) names.

Tooling & tests

• ESLint flat config for Vue + TS, Prettier, and a .prettierignore.
• Vitest + @vue/test-utils + jsdom: unit tests for all six sort algorithms
  plus an app-mount smoke test (7 tests).
• GitHub Actions CI (Node 24) running lint → format → type-check → test →
  build on every PR and on pushes to main.
• netlify.toml pinning the production build to Node 24 (required by Vite 8).

Defaults & fixes

• The app now defaults to dark mode with an initial dataset of 60 bars.
• Fixed a latent selection-sort bug: a malformed var(--yellow-300 value
  (missing closing paren) meant the "smallest value" highlight never rendered.
• Removed dead code (COLORS_DARK, THEMES.file).

Verification

• Full gate passes from a clean npm ci.
• Verified end-to-end (dev server and production build): the UI renders under
  Aura, the light/dark toggle flips the whole UI (Select, Dialog, Toast,
  Slider, Buttons, background), all six algorithms select and sort to
  completion, and the info Dialog and Toast work — with zero console errors.

See CHANGELOG.md for the full list.