tui: pasting a few KB of text renders the whole paste and hangs #52422

Summary

Pasting a few KB of text into the TUI prompt renders the entire text and hangs opencode indefinitely. In v1.x pastes were collapsed and did not render the full text, so this is a regression.

Environment

• opencode version: v2.0.20
• OS: Windows 11 Pro (Windows NT 10.0.26200, x64)
• Terminal: TERM=xterm-256color, COLORTERM=truecolor, TERM_PROGRAM unset, WT_SESSION unset (terminal app could not be identified from the environment)
• Shell: cmd.exe (COMSPEC=C:\WINDOWS\system32\cmd.exe)
• Install/channel: latest
• Active plugins: none configured in ~/.config/opencode/opencode.json or opencode.jsonc; a local plugin file exists at ~/.config/opencode/plugins/herdr-agent-state.js

Reproduction

1. Open opencode v2.0.20 in a terminal (TUI).
2. Copy roughly 10-100 lines of text (a few KB).
3. Paste it into the prompt input.
4. The full pasted text renders in the input and opencode stops responding.

Expected Behavior

The paste is collapsed into a placeholder or summary, as in v1.x, and the TUI stays responsive.

Actual Behavior

The entire pasted text is rendered in the prompt and the TUI hangs. It stays stuck and requires a restart.

Additional Context

• Regression: v1.x collapsed pastes, v2.0.20 renders the full text.
• Reproducible consistently with a few KB of text; exact size not measured.
• Workaround: none found, the user avoids pasting long text.