CREATE TABLE IF NOT EXISTS voice_whispers (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    target_type ENUM('user', 'channel') NOT NULL,
    target_id INT NOT NULL,
    whisper_key VARCHAR(50) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    UNIQUE KEY (user_id, whisper_key),
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;