[Feature Request] Option to stream multi-line ASCII art output without truncation

Summary

When Claude Code runs commands that output ASCII/Unicode art (like chafa, jp2a, ascii-image-converter, etc.), the output is truncated after ~3 lines with a "+N lines (ctrl+o to expand)" message. This makes it difficult to use terminal-based image rendering tools within Claude Code sessions.

Current Behavior

● Bash(chafa -f symbols image.png)
└ ⠀⠀⠀⠀⠀⠀⣴⠶⠒⠈
  ⠀⠀⠀⠀⢀⠀⠄⠀⠀
  ... +12 lines (ctrl+o to expand)

Users must press Ctrl+O to see the full output, which breaks the conversational flow.

Proposed Solution

Add an option to allow specific command outputs (or outputs matching certain patterns) to stream fully without truncation. Possible approaches:

1. Command allowlist: Allow users to configure commands whose output should never be truncated (e.g., chafa, viu, jp2a)

1. Output size threshold: Increase the truncation threshold for outputs that are primarily Unicode block/braille characters

1. Inline flag: Add a flag like --no-truncate that Claude can use when it knows the output should be displayed in full

1. Auto-detect ASCII art: Detect when output consists primarily of Unicode drawing characters and display it fully

Use Case

I'm building a wrapper script (imgshow) using chafa to display images in the terminal as ASCII/Unicode art. This works perfectly in a regular terminal, but within Claude Code the output is always truncated, requiring manual Ctrl+O expansion.

Example workflow:

# This should display the image inline, but gets truncated
imgshow --stream -m braille -s 40x15 screenshot.png

Environment

• Claude Code CLI
• macOS / iTerm2
• chafa 1.18.0

Related Issues

• #2266 (Terminal Graphics Protocol Support) - related but focuses on Sixel/Kitty/iTerm2 protocols rather than plain text output
• #14280 (Stream bash command output in real-time) - related streaming concern for VS Code

Additional Context

The chafa tool can output in multiple formats:

• symbols mode: Uses Unicode block/braille characters with ANSI colors
• ASCII mode: Pure ASCII characters

Even pure ASCII output with no escape sequences gets truncated, so this isn't about ANSI code handling - it's about the CLI's multi-line output truncation behavior.