TableFormatter transformer

[roxspring]

Implement a transformer that pads GFM table columns to consistent widths for readable plain-text rendering.

Scope

• Visits all TableBlock nodes (requires commonmark-java TablesExtension)
• Two-pass approach:
  1. Collect all cell content widths column-by-column to find the maximum per column
  2. Re-emit each row with cells padded to the column maximum
• Alignment markers (---, :---, ---:, :---:) are also padded consistently

Notes

• Uses org.commonmark.ext.gfm.tables.TableBlock, TableHead, TableBody, TableRow, TableCell node types from commonmark-ext-gfm-tables
• Table manipulation operates directly on the AST; re-rendering is handled by MarkdownFormatter

Acceptance criteria

• All columns in a table are padded to consistent widths
• Alignment markers are preserved correctly
• Tables with a single column work correctly
• Non-table content is unaffected