feat: add tree-shakeable entrypoints and launch polish

[tonyblu331]

Summary

• remove the CI badge while keeping npm version, downloads, bundle size, and license badges
• add tree-shake-friendly subpath exports for width, lines, range, and factory imports
• reduce shared Pretext coupling for width/range entrypoints by avoiding full layout in line counting
• replace the README/banner SVG with a clearer before/after visual that shows target preservation
• keep SEO/GEO metadata from the site polish and bump the package to 0.4.0 for the next release

Validation

• vp check
• vp test

Note: I did not run a build, per project instructions.