D1 Tables & ERD

+-----------------------------------------------------------------------------+
|                              ENTITY RELATIONSHIPS                            |
+-----------------------------------------------------------------------------+

+---------------------+       +---------------------+       +---------------------+
|    memory_users     |       |   memory_sessions   |       |   memory_messages   |
+---------------------+       +---------------------+       +---------------------+
| id          TEXT PK |--+    | id          TEXT PK |--+    | id       INTEGER PK |
| github_id   TEXT UK |  |    | user_id     TEXT FK |  |    | session_id  TEXT FK |
| github_login   TEXT |  |    | title          TEXT |  |    | role           TEXT |
| created_at INTEGER  |  |    | state          TEXT |  |    | content        TEXT |
+---------------------+  |    | created_at INTEGER  |  |    | timestamp   INTEGER |
                         |    | metadata       TEXT |  |    | metadata       TEXT |
                         |    +---------------------+  |    +---------------------+
                         |              ^              |              ^
                         |              |              |              |
                         +--------------+              +--------------+
                              owns (1:N)                    has (1:N)

+-------------------------+
|  memory_session_tokens  |
+-------------------------+
| token         TEXT PK   |
| user_id       TEXT FK   |◀--- memory_users.id (1:N owns)
| expires_at    INTEGER   |
+-------------------------+

CREATE TABLE memory_users (
  id TEXT PRIMARY KEY,
  github_id TEXT UNIQUE NOT NULL,
  github_login TEXT NOT NULL,
  created_at INTEGER NOT NULL
);

CREATE TABLE memory_sessions (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL,
  title TEXT,
  state TEXT DEFAULT 'active',
  FOREIGN KEY(user_id) REFERENCES memory_users(id)
);

CREATE TABLE memory_messages (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  session_id TEXT NOT NULL,
  role TEXT CHECK(role IN ('user','assistant','system')),
  content TEXT NOT NULL,
  FOREIGN KEY(session_id) REFERENCES memory_sessions(id)
);

CREATE INDEX idx_memory_messages_session ON memory_messages(session_id, timestamp ASC);
CREATE INDEX idx_memory_messages_content ON memory_messages(session_id, content);

SELECT * FROM memory_sessions 
WHERE user_id = ? 
ORDER BY updated_at DESC 
LIMIT 20;

SELECT * FROM memory_messages 
WHERE session_id = ? AND content LIKE ? 
ORDER BY timestamp;