perf(package): publish tree-shakeable component and hook entry points

[codeacme17]

Parent

#114

Summary

Publish modular, tree-shakeable component and hook entry points so consumers pay only for the Echo UI features they import.

The current distributed module behaves like a pre-bundled application artifact. Importing a basic control, Card, or a single icon can retain most of Echo UI together with Tone.js and visualization-related code. This makes small imports unexpectedly expensive and prevents consumers from relying on normal ESM tree-shaking.

Scope

• Separate the modular ESM output from the UMD or all-in-one distribution artifact.
• Publish focused public entry points for components, hooks, icons, and visualization features where they provide meaningful isolation.
• Preserve the package root as a backward-compatible convenience entry.
• Ensure non-audio components do not retain Tone.js.
• Ensure basic controls and icons do not retain visualization-only code.
• Keep CSS discoverable and correctly marked as a side effect without marking all JavaScript modules as side-effectful.
• Generate type declarations that resolve correctly for root and focused imports.
• Verify package exports in supported ESM and CommonJS consumer configurations.
• Make peer and runtime dependency boundaries explicit.
• Add bundle regression fixtures for representative public imports.
• Document the recommended import forms and any older-bundler caveats.

Acceptance criteria

• Importing a single icon stays below the approved single-icon gzip budget.
• Importing Button, Card, or another basic component stays below the approved basic-component budget.
• A basic component bundle contains neither Tone.js nor visualization-only dependencies.
• A focused audio-hook import contains only the dependencies required by that hook.
• A focused visualization import does not force unrelated controls into the consumer bundle.
• The existing root import remains functional.
• The UMD build remains available if it is part of the supported distribution contract.
• Root and focused imports resolve valid type declarations.
• CSS behavior remains compatible with existing consumers.
• React 18 and React 19 consumer fixtures continue to build.
• Package-artifact verification checks the contents consumers actually install.
• Bundle budgets are enforced by the performance harness.

Compatibility requirements

• Treat focused entry points as additive.
• Avoid renaming existing public component or hook exports.
• Preserve the current CSS entry point unless a migration path is documented.
• Document any unavoidable resolution limitation for older bundlers.

Out of scope

• Runtime optimization of analyzers or visualizers.
• Redesigning component APIs.
• Removing the package root export.
• Replacing Tone.js or D3 solely to improve package size.

Validation

• Run all consumer build fixtures against the packed package artifact.
• Compare focused imports with the root import using the same bundler configuration.
• Inspect output to verify that unrelated dependencies are absent rather than merely compressed.
• Run unit tests, typecheck, lint, library builds, and example builds.

Dependencies

Blocked by: #115.