feat(tui): show plugin and MCP tool input as a readable block - #54707

Note: I'm aware v1 is now the maintenance branch and new features go to v2 only. This PR is here for others to use, and I'll submit the v2 version once I've migrated my whole plugin system to it.

Issue for this PR

Closes #54703

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

With syntax.tool_input: true in tui.json, a plugin or MCP tool's input that is all primitives and fits 80 characters keeps today's [key=value] line. Anything else becomes a block (util/tool-input.ts): one key per row, keys and values in different colors, values colored by type, strings unquoted with their newlines, tabs and quotes as themselves, nested objects indented under their key, and lists in compact YAML (- items at their key's indent). Until the block is clicked, every value takes exactly one row, cut with a muted … where it stops fitting, so the collapsed block shows keys and the start of each value; the width is the block's measured width, taken on layout and resize only. Clicking shows everything whole.

Keys and values never draw in red, which means a failed tool call in the transcript: the colors come from theme/tool-code.ts (shared with #54704), where every red or error-colored syntax slot takes a non-red alternative. Keys use the property color, falling back to the function color, then the type color.

When the generic output toggle is off, a call with a response still shows "Click to expand", and expanding draws the response under the input, so the block never leaves a stored response unreachable (toolOutputReach). Without syntax.tool_input the toggle stays in charge as today.

Off by default, so the transcript looks as it does now. Documented in tui.mdx.

How did you verify your code works?

• bun typecheck; bun test test/util test/config.test.tsx test/cli/tui test/tool-code-theme.test.ts: 117 pass, including collapsed render frames at 40, 80 and 160 columns (one row per value, never wider than the block), the compact YAML layout, cutting by display width, and a check of every built-in theme for red slots.
• A real TUI at 80 and 160 columns with an MCP call carrying nested input and a question list.
• A real TUI at 40, 80 and 160 columns with the output toggle off and a stored Perplexity search response: the block shows "Click to expand", and a click through a real PTY client shows the response with "Click to collapse"; with syntax.tool_input off the inline row is unchanged.

Screenshots / recordings

Collapsed, at 80 columns:

# vibeterm_async_question
questions:
- header: Paste dialog v4
  question: Live as vt-233 on desktop and m4max (fork 00ea612cb9, PR #54…
  options:
  - label: Works
    description: Buttons, tab and hint behave as listed in the report ab…
  - label: Something's off
    description: Say what differs from the report, with the exact keys y…

Click to expand

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

This PR is AI generated, but under direct supervision and on request of @Nowaker.