Function renderTimeline

src/context/approach-diff.ts:99–114

(matches: ApproachMatch[], k = 5)

 * skipped; capped at `k` (default 5, per the "last 5 approaches with dates" spec). PURE.
 */
export function renderTimeline(matches: ApproachMatch[], k = 5): string[] {
  const dated = matches
    .map(m => ({ m, t: m.at ? Date.parse(m.at) : NaN }))
    .filter(x => Number.isFinite(x.t))
    .sort((a, b) => a.t - b.t)
    .slice(-k);
  if (dated.length < 2) return [];
  const lines = ['', `Timeline (oldest → newest):`];
  dated.forEach(({ m }, i) => {
    const date = m.at!.slice(0, 10);
    const glyph = i === dated.length - 1 ? '●' : '○';
    const mark = m.verified === true ? ' ✓' : m.verified === false ? ' ⛔' : '';
    lines.push(`  ${glyph} ${date}${mark}  ${head(m.text, 76)}`);
  });
  return lines;
}

/**
 * Render top-K matches as a visual comparison: the best approach in full, then each alternative