feat: additional export formats (Markdown, HTML)

[mpryor]

Summary

Add Markdown table and HTML export formats to the W (write) and --no-tui -o output options.

Problem

When sharing analysis results in Slack, GitHub issues, or documentation, users need to manually convert CSV/JSON output to Markdown tables or HTML. Direct export would save a step.

Features

• W write and -o flag support for:
  • markdown — pipe-delimited Markdown table with header separator
  • html — basic HTML table with <table>, <thead>, <tbody> tags
• Respects current column visibility and sort order

Technical Considerations

• Markdown tables need column width handling for readability
• HTML export could optionally include inline CSS from the current theme
• Should work with both interactive W and batch --no-tui -o modes

Related

• Extends existing export formats (csv, tsv, json, raw)