fix: handle URLs with balanced parentheses in URL detection

[ericjypark]

Problem

URLs containing parentheses — such as Wikipedia links like https://en.wikipedia.org/wiki/Rust_(programming_language) — are incorrectly truncated. The URL regex character class excludes ( and ), so the match stops at the first parenthesis. Additionally, TRAILING_PUNCTUATION unconditionally strips ), breaking URLs where parentheses are part of the path.

Fix

• Add () to the URL regex character class so parentheses are captured
• Remove ) from TRAILING_PUNCTUATION to preserve balanced parens
• Add a balanced-paren stripping pass: only strip trailing ) when the URL has more close-parens than open-parens (handles the common case of a URL wrapped in prose parentheses like (see https://...))

Test Plan

• bun test lib/url-detection.test.ts — 24/24 pass (4 new tests for parens handling)
• biome check . — clean
• tsc --noEmit — clean
• Existing test 'strips trailing parenthesis' with (see https://example.com) still passes

[diegosouzapw]

Hi @ericjypark! 👋

Your work on this PR inspired a commit in my fork diegosouzapw/ghostty-web.
I ported the URL detection fix for balanced parentheses and added you as co-author in the corresponding commit — thank you for the contribution!

I'm working on OmniRoute, a project that provides free access to LLM models, and I'm planning to use ghostty-web as the terminal component there. Your work is part of what makes that possible. 🙏

Feel free to check it out — contributions and feedback are very welcome!