Fix table column alignment with Unicode wide characters

[llimllib]

Summary

Tables with emoji (like ✅ and ❌) or other wide Unicode characters (CJK, etc.) were rendering with misaligned columns because the code was using character count instead of display width.

Changes

• Added unicode-width crate dependency
• Created display_width() helper method that strips ANSI codes and calculates Unicode display width
• Updated table column width calculation to use Unicode width
• Updated table cell alignment to use Unicode width
• Updated text wrapping indent calculations to use Unicode width

Before

┌────────┬────────┐
│ Method │ Status │
├────────┼────────┤
│ yaml   │ ✅      │   <- Column too wide, pipes misaligned
│ env    │ ❌      │
└────────┴────────┘

After

┌────────┬────────┐
│ Method │ Status │
├────────┼────────┤
│ yaml   │ ✅     │   <- Properly aligned
│ env    │ ❌     │
└────────┴────────┘

Testing

Added unit tests to verify:

• Basic table with emoji alignment
• The specific table from issue fix broken markdown table #28

All 115 existing tests pass.

Session transcript

transcripts/29-fix-unicode-table-alignment.html

Fixes #28