Function selectInjectedFacts

src/context/memory-select.ts:52–70

(facts: string[], opts: MemorySelectOptions = {})

 * newest others until the token budget is exhausted — preserving the input order.
 */
export function selectInjectedFacts(facts: string[], opts: MemorySelectOptions = {}): string[] {
  if (opts.mode !== 'lightweight') return facts;
  const budget = opts.injectMaxTokens ?? 2000;
  const out: string[] = [];
  let spent = 0;
  // Important facts are always in and don't draw from the budget.
  for (const f of facts) if (isImportantFact(f)) out.push(f);
  // Fill the rest newest-first until the budget runs out, keeping the original ordering in the result.
  const kept = new Set(out);
  const filler: string[] = [];
  for (const f of facts) {
    if (kept.has(f)) continue;
    const cost = estimateTokens(f);
    if (spent + cost > budget) continue;
    spent += cost; filler.push(f); kept.add(f);
  }
  // Return in the original (newest-first) order, important + budgeted-filler interleaved as they appeared.
  return facts.filter(f => kept.has(f));
}