Improve error message when xclip/wl-paste is not installed for image paste

Problem

On Linux, when a user tries to paste an image using Ctrl+V (the chat:imagePaste action) without xclip or wl-paste installed, Claude Code displays:

"No image found in clipboard. Use ctrl+v to paste images."

This is misleading — the clipboard does contain an image, but Claude Code cannot read it because the required tool is missing.

Root Cause

The checkImage command on Linux runs:

xclip -selection clipboard -t TARGETS -o 2>/dev/null | grep -E "image/(png|jpeg|jpg|gif|webp|bmp)" || wl-paste -l 2>/dev/null | grep -E "image/(png|jpeg|jpg|gif|webp|bmp)"

Both xclip and wl-paste fail silently (due to 2>/dev/null), so the grep finds nothing, and Claude Code concludes there is no image.

Interestingly, the copy-to-clipboard failure path already has a helpful message:

"Failed to copy to clipboard. Make sure \xclip\ or \wl-copy\ is installed on your system and try again."

But the read/paste image path lacks this check.

Expected Behavior

When xclip and wl-paste are both missing, the error message should indicate the actual problem, e.g.:

"Cannot read clipboard image. Please install \xclip\ or \wl-clipboard\ and try again."

Suggested Fix

Before running checkImage, check if xclip or wl-paste exists in $PATH. If neither is found, show the tool-missing message instead of "No image found in clipboard."

Environment

• OS: Rocky Linux 9 (X11 session)
• Claude Code version: 2.1.62
• Workaround: sudo dnf install xclip