Replace D3 DOM rendering with React SVG charts

[skratchdot]

Summary

Move ownership of chart SVG children from D3 to React, with Tailwind styling and no intended redesign. Audio timing remains outside React.

Rendering and behavior

• Render bars, sort markers, trajectory paths, and the envelope diagram through React components.
• Publish frame data, position, and visualization mode from the player controller; charts subscribe to those snapshots.
• Preserve input dragging, hover feedback, pointer capture/cancellation, playback highlighting, and renderer switching.
• Memoize trajectory geometry by recorded frames and preserve item identity when values repeat.
• Remove imperative renderers, d3-selection, and the entire visualizations.css stylesheet. Keep D3 array, scale, color, and shape calculation helpers.

Structure and types

• Keep React rendering under components/visualizations.
• Rename audio/envelope-diagram.ts to audio/envelope.ts now that it only contains calculations and formatting.
• Introduce typed create-trajectories.ts with frame, point, and result types.
• Replace visualization-registry.mjs with visualization-types.ts, exporting mode labels and VisualizationType.
• Update documentation and the README dependency synopsis.

Verification

• pnpm run check passed: lint, formatting, spelling, TypeScript, 362 unit tests, and production build.
• All 38 Playwright browser tests passed using local Chrome.
• Added tests for duplicate-value trajectory identity, empty/single-item geometry, hover styling, and pointer cancellation.
• git diff --check passed.
• Existing large-chunk build warnings remain. Audible output was not manually verified; a quick playback/listening check is still recommended.