CREATE TABLE IF NOT EXISTS todos (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    text TEXT NOT NULL,
    priority TEXT NOT NULL DEFAULT 'medium',
    project TEXT,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
    completed_at TEXT
);

CREATE TABLE IF NOT EXISTS todo_tags (
    todo_id INTEGER NOT NULL REFERENCES todos(id) ON DELETE CASCADE,
    tag TEXT NOT NULL,
    PRIMARY KEY (todo_id, tag)
);