CREATE TABLE users (
 id INTEGER PRIMARY KEY AUTOINCREMENT,
 nickname TEXT NOT NULL UNIQUE,
 nickname_key TEXT NOT NULL UNIQUE,
 email TEXT NOT NULL,
 email_key TEXT NOT NULL UNIQUE,
 password_hash TEXT NOT NULL,
 created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
 updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE user_sessions (
 token TEXT PRIMARY KEY,
 user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
 expires_at TEXT NOT NULL,
 created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
);
CREATE INDEX idx_user_sessions_user ON user_sessions(user_id);
CREATE TABLE password_reset_tokens (
 token TEXT PRIMARY KEY,
 user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
 expires_at TEXT NOT NULL,
 used_at TEXT,
 created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
);
CREATE INDEX idx_password_reset_user ON password_reset_tokens(user_id);