Add opt-in URLPattern parser with nested route support

[molefrog]

Fixes #563 by adding urlPatternParser exports from wouter/url-pattern and wouter-preact/url-pattern. <Router parser={urlPatternParser}> uses the native URLPattern API for pathname syntax and groups, matching the longest valid prefix for nested routes. A browser or runtime with native URLPattern support is required.

The optional adapter measures 223 B minified and Brotli compressed; default bundles and runtime dependencies are unchanged. Parser typings accept objects with a compatible exec method.

Validated with native URLPattern in Bun 1.4.2: 269 passing tests, one existing skip, 100% line coverage, TypeScript, lint, and size limits.

[bolt-new-by-stackblitz]

Run & review this pull request in StackBlitz Codeflow.

[github-actions]

size-limit report 📦

Path	Size
packages/wouter/src/index.js	2.29 KB (0%)
packages/wouter/src/use-browser-location.js	555 B (0%)
packages/wouter/src/memory-location.js	729 B (0%)
packages/wouter/src/use-hash-location.js	720 B (0%)
packages/wouter-preact/src/index.js	2.18 KB (0%)
packages/wouter-preact/src/use-browser-location.js	488 B (0%)
packages/wouter-preact/src/use-hash-location.js	645 B (0%)
packages/wouter-preact/src/memory-location.js	664 B (0%)
packages/wouter/src/url-pattern.js	223 B (+100% 🔺)
packages/wouter-preact/src/url-pattern.js	223 B (+100% 🔺)