#20330 Agent chat: steps read as one list; a thought shows in full

Summary

Leo (cmux NEXT, agent chat transcript, macOS 27) asked for a quiet, consistent list of a turn's steps:

• Thoughts: a Thought row showed one line and popped a tooltip with the full thought on hover. A thought now shows in full on its row, wrapped after a muted "Thought" label. There's nothing to open and no tooltip.
• No hover styling: tool rows brightened and revealed their chevron on hover. They no longer change on hover, and the disclosure chevron is there at rest in a quiet color. A command row's hover tooltip is removed too; its full command shows when the row opens.
• One row style: "Background task finished" drew in the caption size in a 22px row with its own 4px margins. It's now a tool row: same font, 26px height and terminal icon as a Ran row.
• One rhythm: steps in the same transcript row sat 26px apart, but a step in the next transcript row sat 10px lower (the row's 8px bottom padding plus the next group's 2px top margin, with a 34px row floor). A step row next to another step row now adds no gap, so tool calls, thoughts and background-task ends keep one 26px rhythm across rows.

Testing

• webviews/test/agent-pane-step-rows.test.ts (Chromium, browser lane): a live turn with Ran, Thought, Ran, a background task's end and Read.
  • Every one-line step is 26px tall, all in one font size, each starting where the one above ends.
  • The thought shows its full text, wraps, and has no title.
  • A row's color and chevron don't change on hover, and the chevron is visible at rest.
  • Red on the test commit, green on the fix; see react-apps-check on each head.
• webviews/test/thought-row.test.tsx (jsdom): red on base (only the first line was drawn), green after.
• Gallery: agent-pane.transcript thought-row play checks the full text, no toggle and no tooltip; thought-find marks the match in the thought's text.
• bun run check passes.

Changelog

• Changed: agent chat shows each thought in full, and tool, thought and background-task rows share one style and spacing with no hover effects.

🤖 Generated with Claude Code

---

^{Need help on this PR? Tag @codesmith-bot with what you need.}

---

Summary by cubic

Agent chat steps now read as one list: tool calls, thoughts, and background-task ends share one 26px row style and spacing, with no hover effects. A thought shows its full text on its row instead of one line with a tooltip. Until now, the background task's end drew in a smaller 22px row with its own margins, a step in the next transcript row sat 10px lower, and hover brightened a row and revealed its chevron; the Thought label and a step's chevron now sit in a quieter color.

Testing

• agent-pane-step-rows.test.ts drives a live turn in Chromium and checks row heights, rhythm, full thought text, and hover behavior.
• transcript-thought.test.ts checks the gallery plays: a thought renders fully with no button, tooltip, or expand state (the play hovers it), and Find marks the match in the thought's text.