Function unifiedDiff

packages/shell/src/filesystem.ts:1690–1703

(
  a: string,
  b: string,
  labelA: string,
  labelB: string,
  contextLines = 3
)

// ── Diff helpers ─────────────────────────────────────────────────────

function unifiedDiff(
  a: string,
  b: string,
  labelA: string,
  labelB: string,
  contextLines = 3
): string {
  if (a === b) return "";

  const linesA = a.split("\n");
  const linesB = b.split("\n");
  const edits = myersDiff(linesA, linesB);
  return formatUnified(edits, linesA, linesB, labelA, labelB, contextLines);
}

type Edit = {
  type: "keep" | "delete" | "insert";