Tool card args preview shows full JSON regardless of length, making cards unreadable

[FernandoCelmer]

Problem

In media/chat-tools.js, the argsPreview() function dumps the entire serialized arguments object into the tool card header:

function argsPreview(args) {
  try {
    return JSON.stringify(args);
  } catch {
    return String(args);
  }
}

When the agent calls write_file or edit_file with a large file body, or bash with a long script, the one-line preview in the collapsed card header becomes hundreds of characters — the tool name is pushed off-screen and the preview is meaningless.

Steps to reproduce / context

1. Ask CodeLoop to write a file with more than ~50 lines.
2. Watch the write_file tool card — the header overflows with the full file content serialized as JSON.

Expected behavior

The args preview in the header (collapsed state) should be truncated to a short summary (e.g. 80 characters) with an ellipsis. The full JSON is already visible in the expanded card body (argsPre), so no information is lost.

Suggested fix

const MAX_PREVIEW = 80;
function argsPreview(args) {
  try {
    const s = JSON.stringify(args);
    return s.length > MAX_PREVIEW ? s.slice(0, MAX_PREVIEW) + "…" : s;
  } catch {
    return String(args).slice(0, MAX_PREVIEW);
  }
}