refinement fixes

packages/memory-service/src/episodic/index.js

@@ -172,6 +172,30 @@ function getRecentEpisodes(sessionId, limit = EPISODIC.DEFAULT_RECENT_LIMIT) {
 }
 
 
+// Aggregate stats for a session — count, total tokens, and highest episode id.
+// Lets summarization check the token threshold without pulling every episode row.
+function getSessionEpisodeStats(sessionId) {
+  const db = getDB();
+  return db.prepare(`
+    SELECT COUNT(*)                      AS count,
+           COALESCE(SUM(token_count), 0) AS totalTokens,
+           COALESCE(MAX(id), 0)          AS maxId
+    FROM episodes
+    WHERE session_id = ?
+  `).get(sessionId);
+}
+
+// Episodes newer than a given id, in chronological order. Summarization uses
+// this to fetch only the un-summarized tail rather than the whole session.
+function getEpisodesSince(sessionId, afterId) {
+  const db = getDB();
+  return db.prepare(`
+    SELECT * FROM episodes
+    WHERE session_id = ? AND id > ?
+    ORDER BY id ASC
+  `).all(sessionId, afterId).map(parseRow);
+}
+
 // Searches episodes using FTS5 full-text search, ordered by relevance, with a limit
 function searchEpisodes(query, limit = EPISODIC.DEFAULT_SEARCH_LIMIT, sessionIds = null) {
   const db = getDB();
@@ -247,6 +271,8 @@ module.exports = {
   getEpisode,
   getEpisodesBySession,
   getRecentEpisodes,
+  getSessionEpisodeStats,
+  getEpisodesSince,
   searchEpisodes,
   deleteEpisode,
   getEpisodesByProject