Long text pasted into input auto-converts to paste attachment with no content on model side

Bug Report

Description:
When a long text is pasted into the input, it gets automatically converted to a paste attachment. However, the attachment arrives with no content on the model side — the model cannot read it. Real file uploads work correctly.

Steps to Reproduce:

1. Paste a large block of text into the Claude Code input
2. Observe it gets auto-converted to a paste attachment
3. The model receives the attachment but sees no content

Expected Behavior:
The pasted text should be accessible to the model, either as inline text or as a readable attachment.

Actual Behavior:
The attachment arrives empty/with no content on the model side.

Environment:

• OS: macOS Tahoe 26.5
• Claude Desktop App: 1.20186.1 (df1d8a)

Additional Context:

• Real file uploads (dragged/attached files) work fine — content is accessible
• Only paste-triggered auto-conversion is affected