Markdown table columns misalign when cells contain emoji characters

[bghgary]

Description

Markdown tables containing emoji characters (e.g. 🟡, 🟢, ✅, ❌, ⏳) render with broken column alignment when the terminal window is not wide enough. The columns wrap incorrectly and raw ANSI escape code fragments (e.g. [38 ;2... 80;1 80;1 80ms) leak into the rendered output.

Steps to Reproduce

1. Have a terminal window at a moderate width (not maximized)
2. Ask Copilot CLI to produce a markdown table that includes colored emoji in cells, for example:

| Name | Status | Count |
|------|--------|-------|
| Foo  | 🟢 open | 5✅ 2❌ |
| Bar  | 🟡 draft | 3✅ 1⏳ |

3. Observe the rendered table — columns are misaligned, text wraps mid-cell, and ANSI escape codes appear as raw text

Expected Behavior

The table should render with correct column alignment regardless of emoji presence. Emoji characters are typically double-width in terminals, but the markdown renderer appears to calculate them as single-width, causing columns to overflow and wrap.

Workaround

• Widening the terminal window makes the table render correctly
• Using single-width Unicode symbols (✓, ✗, ●, ○) instead of emoji avoids the issue

Environment

• OS: Windows
• Terminal: Windows Terminal
• Copilot CLI version: 1.0.27