tui: UnsupportedContentType crash

Summary

The OpenCode TUI crashed with an UnsupportedContentType error during normal operation.

Environment

• opencode version: 2.0.10
• OS: Linux 6.8.0-139-generic (x86_64)
• Terminal: Orca 1.4.199 (TERM=xterm-256color, COLORTERM=truecolor)
• Shell: /bin/bash
• Install/channel: latest release
• Active plugins: gentle-logo.tsx (TUI plugin)

Reproduction

1. Run opencode in the TUI
2. TUI crashes with UnsupportedContentType

Expected Behavior

TUI operates normally without crashing.

Actual Behavior

TUI crashes with the following error:

ClientError: UnsupportedContentType
    at S (/$bunfs/root/chunk-ar61a8at.js:13:25549)
    at async <anonymous> (/$bunfs/root/chunk-ar61a8at.js:2:912)
    at processTicksAndRejections (native:7:39)

Additional Context

• The crash occurred during normal TUI usage.
• Prior to this session, two TUI plugins (opencode-subagent-statusline and a literal <PORTABLE_PATH> placeholder) were failing with NpmInstallFailedError due to peer dependency conflicts with @opencode/plugin@2.0.10. Those entries have since been removed from config.
• The UnsupportedContentType error may be related to the TUI receiving an unexpected response content type from the background service or an API call.

Start by reproducing the crash while running opencode in the TUI with the reported Linux, terminal, shell, version, and plugin context. Trace the TUI or background-service request that produces UnsupportedContentType; done means normal TUI operation without the crash, with a regression test if an existing test location is identified.