summary system backend implementation

packages/memory-service/src/db/schema.js

@@ -41,12 +41,17 @@ const schema = `
   CREATE TABLE IF NOT EXISTS summaries (
     id            INTEGER PRIMARY KEY AUTOINCREMENT,
     session_id    INTEGER REFERENCES sessions(id) ON DELETE CASCADE,
+    project_id    INTEGER REFERENCES projects(id) ON DELETE CASCADE,
     content       TEXT    NOT NULL,
+    token_count   INTEGER,
     episode_range TEXT,
     created_at    INTEGER NOT NULL DEFAULT (unixepoch()),
     metadata      TEXT
   );
 
+  CREATE INDEX IF NOT EXISTS idx_summaries_session ON summaries(session_id);
+  CREATE INDEX IF NOT EXISTS idx_summaries_project ON summaries(project_id);
+
   CREATE INDEX IF NOT EXISTS idx_episodes_session 
     ON episodes(session_id);
   CREATE INDEX IF NOT EXISTS idx_episodes_created