feat: add memory selection and TTL decay

runners/agent-runner/src/memory-selection.ts

@@ -0,0 +1,73 @@
+export interface SelectedCompactMemory {
+  content: string;
+  keywords: string[];
+  memoryKind: string | null;
+}
+
+const MAX_SELECTED_MEMORIES = 3;
+
+const MEMORY_PATTERNS: Array<{
+  kind: string | null;
+  regex: RegExp;
+  keyword: string;
+}> = [
+  { kind: 'room_norm', regex: /(규칙|원칙|금지|반드시|하지 않|세션 시작 시에만|새 세션 시작 시에만)/i, keyword: 'rule' },
+  { kind: 'preference', regex: /(선호|원함|원한다|원하는|원했다)/i, keyword: 'preference' },
+  { kind: 'decision', regex: /(합의|결정|방향|기준|우선|책임지는 방향)/i, keyword: 'decision' },
+  { kind: 'project_fact', regex: /(owner|reviewer|trigger|모드|메모리|기억|세션 리셋|recall|persist|compact)/i, keyword: 'memory' },
+];
+
+function normalizeSentence(raw: string): string | null {
+  const normalized = raw
+    .trim()
+    .replace(/^[-*]\s*/, '')
+    .replace(/\s+/g, ' ');
+  return normalized ? normalized : null;
+}
+
+function splitSummaryIntoSentences(summary: string): string[] {
+  return summary
+    .split(/\n+|(?<=[.!?。])\s+/)
+    .map(normalizeSentence)
+    .filter((value): value is string => Boolean(value));
+}
+
+function classifyMemorySentence(content: string): SelectedCompactMemory | null {
+  if (!content) return null;
+
+  const matchedPatterns = MEMORY_PATTERNS.filter(({ regex }) => regex.test(content));
+  if (matchedPatterns.length === 0) return null;
+
+  const primary = matchedPatterns[0];
+  const keywords = [
+    ...new Set(
+      matchedPatterns
+        .map((pattern) => pattern.keyword)
+        .filter(Boolean),
+    ),
+  ];
+
+  return {
+    content,
+    keywords,
+    memoryKind: primary?.kind ?? null,
+  };
+}
+
+export function selectCompactMemoriesFromSummary(
+  summary: string,
+  roomKey: string,
+): SelectedCompactMemory[] {
+  if (!summary.trim()) return [];
+
+  const selected = splitSummaryIntoSentences(summary)
+    .map((sentence) => classifyMemorySentence(sentence))
+    .filter((value): value is SelectedCompactMemory => Boolean(value))
+    .slice(0, MAX_SELECTED_MEMORIES)
+    .map((entry) => ({
+      ...entry,
+      keywords: [...new Set([roomKey, ...entry.keywords])],
+    }));
+
+  return selected;
+}