Fix CommonJS package entrypoint

[alejandrorivas-pixel]

Summary

• update the CommonJS package entrypoint from ./dist/index.cjs.js to ./dist/index.cjs
• keep the existing ESM and types entries unchanged

Why

The build already emits dist/index.cjs, but the published package metadata points CommonJS consumers at dist/index.cjs.js. As a result, require('@svar-ui/react-core') fails with MODULE_NOT_FOUND in a clean install.

Validation

Reproduced against the published package:

npm install @svar-ui/react-core@2.6.0 --ignore-scripts --no-audit --no-fund
node -e "require('@svar-ui/react-core')"
# MODULE_NOT_FOUND ... dist/index.cjs.js

Validated this patch:

npm ci --ignore-scripts
npm run build
npm pack --silent

tmp="$(mktemp -d)"
cd "$tmp"
npm init -y >/dev/null
npm install /path/to/svar-ui-react-core-2.6.0.tgz react@18 react-dom@18 --ignore-scripts --no-audit --no-fund >/dev/null
node -e "const mod = require('@svar-ui/react-core'); console.log(typeof mod)"
node --input-type=module -e "const mod = await import('@svar-ui/react-core'); console.log(typeof mod)"

Both CommonJS require() and ESM import() pass with the packed tarball.

Also ran:

git diff --check