refactor: remove lib, lib-esm references

[joshblack]

Closes #7482

Changelog

New

Changed

• Remove lib, lib-esm references from project

Removed

Rollout strategy

• None; if selected, include a brief description as to why

This is an internal change to config files

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Latest commit: 497da60

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[github-actions]

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[Copilot]

Pull request overview

This PR cleans up remaining build/tooling configuration references to the legacy lib/ and lib-esm/ output folders, aligning the repo with the current dist/-only build output model.

Changes:

• Remove lib/ and lib-esm/ from Turbo build outputs and from various tooling ignore/exclude lists (ESLint, Stylelint, Prettier, Vitest, setup script).
• Update an exports-parsing example comment to reference ./dist/* instead of ./lib-esm/*.

Show a summary per file

File	Description
turbo.json	Drops lib/** and lib-esm/** from build task outputs.
script/setup-react-19.mts	Removes lib/lib-esm from glob ignore list; minor write formatting tweak.
packages/react/vitest.config.browser.mts	Removes lib/lib-esm from Vitest browser exclude list.
packages/react/script/get-export-sizes.cjs	Updates example export-map comment from lib-esm wildcard to dist wildcard.
eslint.config.mjs	Removes lib/lib-esm from global ignore patterns.
.stylelintignore	Removes lib/lib-esm ignore patterns for CSS.
.prettierignore	Removes lib/lib-esm ignore patterns.
.gitignore	Stops ignoring lib/ and lib-esm/ build folders at repo root.

Copilot's findings

• Files reviewed: 7/8 changed files
• Comments generated: 1