fix: prevent sparse spacing in hyphenated words

[monotykamary]

Summary

This PR fixes the sparse spacing issue that occurs when displaying hyphenated words like 'claude-code-action' in both Assistant and User messages in the TUI. Fixes #621.

Problem

Previously, hyphenated words would break at hyphens, creating sparse single-word lines that made the chat interface look broken and difficult to read.

Before:

Solution

After:

• Assistant messages: Use non-breaking hyphens (U+2011) in markdown rendering to prevent word breaks at hyphens
• User messages: Apply non-breaking hyphens before word wrapping and styling
• Textarea component: Modified word boundary detection to treat hyphens as part of words
• Width constraint: Maintained 86 character width limit with precise calculations

Changes Made

1. packages/tui/internal/components/chat/message.go: Updated user message rendering to use non-breaking hyphens
2. packages/tui/internal/components/textarea/textarea.go: Modified word boundary detection in textarea word wrapping
3. packages/tui/internal/util/file.go: Enhanced markdown rendering with hyphen handling

Testing

• Verified both Assistant and User messages display correctly
• Confirmed 86 character width constraint is maintained
• Tested with various hyphenated words and phrases
• No visual regressions in existing functionality

This change significantly improves the readability of hyphenated content in the TUI without affecting any other functionality.

[adamdotdevin]

just a few questions, i'd love to have this fixed, just need to understand the implementation a little better

[monotykamary]

Now that you've pointed it out, I think there might be a more ergonomic way to do this 🤔
also now that we're going for a stretched look

[monotykamary]

Before	After