tui: no setting to always expand tool call arguments and output in the session transcript #50220

Summary

The V2 full-screen TUI has no configuration or keybind to render tool-call
arguments and result output expanded by default. Some tool calls render as collapsed single-line entries and show only '✓execute'.
You need to expand each one manually. The web version exposes this as a display option (Timeline detail → Everything),
but the TUI has no equivalent.

Environment

• opencode version: 2.0.11
• OS: Linux 5.15.153.1-microsoft-standard-WSL2 (linux x64)
• Terminal: TERM=xterm-256color (WSL2, no TERM_PROGRAM/COLORTERM)
• Shell: /bin/bash
• Install/channel: latest (release)
• Active plugins: opencode-stats, ssh-remote, devices (all local, package
  directories)

Reproduction

1. Open the full-screen TUI (opencode).
2. Ask the agent to run any shell command, e.g. echo "hello" via the bash
   tool.
3. Observe the transcript: the tool call renders collapsed, showing only the
   tool name and a short argument preview / one-line result.
4. Search for a way to make it always expanded.

Expected Behavior

There should be a cli.json setting (and/or keybind) to always show expanded
tool-call detail, i.e. each tool call renders its arguments and result output
inline, matching the web version's Timeline detail → Everything mode:

✓ bash [command=echo "hello"]
  command: echo "hello"
  output: hello

A candidate shape consistent with existing settings:

{
  "session": {
    "tool_expansion": "always" // or "collapsed" (default) / "auto"
  }
}

Actual Behavior

No such setting exists. The documented CLI settings
(https://opencode.ai/v2/docs/cli/config) provide only:

• session.grouping: auto | none — affects grouping, not expansion.
• session.toggle.exploration_grouping keybind — grouping only.
• session.toggle.thinking — reasoning blocks only.
• mini.tools / mini.shell_output — apply to opencode mini only, not the
  full TUI.
• composer.shell.select — views output of blocking shell tools in the Shell
  tab, not inline expansion in the transcript.

Observed: with session.grouping: "none", items render separately but still
collapsed; there is no keybind or config that expands arguments and output by
default.