CREATE TABLE IF NOT EXISTS project_comments (
    id INT AUTO_INCREMENT PRIMARY KEY,
    project_id INT NOT NULL,
    user_id INT NOT NULL,
    comment TEXT NOT NULL,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    INDEX idx_project_comments (project_id, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
