Enforce prepared MySQL driver requirement before datasource connection

[Copilot]

• Inspect initialization flow, existing driver status UI, and current init websocket/API structure
• Add init-specific backend MySQL driver status/download logic and websocket events
• Add a dedicated initialization MySQL driver status component with icon/button/progress only
• Wire the new component into the initialization database step and add i18n text
• Run targeted validation for frontend/backend changes and summarize any environment limitations