perf!: use switch for type_name and remove TYPE_NAMES

[bartveneman]

Summary

• CSSNode#type_name is now a switch on the numeric type instead of an object lookup.
• Breaking: the TYPE_NAMES export is removed. Use node.type_name instead of TYPE_NAMES[node.type].
• TypeName is now an explicit string-literal union (it used to be derived from TYPE_NAMES).
• README example updated.

Benchmarks

pnpm run benchmark, walk (node.type_name) in ops/sec, before → after:

File	Before	After	Change
Nerdy.dev	3687	3820	+3.6%
CSS Tricks	411	418	+1.7%
Bootstrap	1956	2027	+3.6%
Tailwind	137	146	+6.6%

The walk (node.type) control rows were flat between runs, and tokenize, parse and traverse did not regress. In a micro-benchmark that reads only type_name on every Bootstrap node, the switch was about 35% faster (about 12.2 ms down to 7.6 ms).

The switch relies on bundling to inline the numeric constants. Running the unbundled .ts sources directly was much slower in my testing, but the published bundle is unaffected.

Test plan

• pnpm vitest --run
• pnpm run lint
• pnpm run check
• pnpm knip

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Generated by Claude Code

[github-actions]

🎉 Package Size Decrease

📦 Package	📏 Base Size	📏 Source Size	📈 Size Change
@projectwallace/css-parser	46.3 kB	46 kB	-233 B

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commit: d2eb86c