Tool cards: let a settled card fold to its header, like thinking blocks

[dragon-defy-sky]

Summary

Thinking blocks fold to a one-line header the moment the model moves past thinking (thinkingFold: preview). Tool cards do not: a settled card always keeps its command header plus up to three body lines, so any turn with several tool calls stays tall and reads nothing like the thinking rows sitting between them.

Expected

A settled tool card should be able to collapse to its header alone (with the existing "…N lines / Ctrl+O expands" hint) — the same settle-fold that thinking already gets — while running cards and errors keep their preview.

Where it lives (verified on 0.19.0)

• lib/types/components/messages/AssistantToolUseMessage.js
  • const TEXT_BODY_MAX_LINES = 3; / const DIFF_BODY_MAX_LINES = 8;
  • const cap = view?.card === 'diff' ? DIFF_BODY_MAX_LINES : TEXT_BODY_MAX_LINES; → capLines(bodyLines, cap, bodyUncapped, ...)
  • capLines() already handles max = 0 cleanly (body becomes the single fold-hint line).
• lib/types/settings/definitions.js exposes every display knob; none controls the tool body budget. foldTerminalCommand only folds a multi-line command header to its first line + count, which still leaves the 3-line body.

Proposal

Add a setting next to thinkingFold, e.g.

toolCardFold: preview | hidden   # default preview == today's 3-line body

hidden caps a settled card's body at 0 lines, keeping the current behavior for:

• running cards (live output stays visible),
• error bodies and the non-zero exit-code / kill-signal lines (they ride outside the cap today),
• Ctrl+O and click expansion.

Evidence that the shape works

Patching that single line to

const cap = isError || isRunning
  ? (view?.card === 'diff' ? DIFF_BODY_MAX_LINES : TEXT_BODY_MAX_LINES)
  : 0;

renders exactly the wanted card: header line + fold hint, expandable via Ctrl+O or a click.

Environment

• dsh-tui 0.19.0, dsh engine 0.2.2-rc.1
• Windows 11, Windows Terminal 1.24, fullscreen layout, thinkingFold: preview

[Lucas2011wastaken]

Issue only accept bug report for non-contributors. plz use discussions.