Introduces a new API endpoint `/terminal_images` to serve generated terminal output images.
- Creates a new file `api_service/terminal_images_endpoint.py` to handle the static file serving.
- Modifies `api_service/api_server.py` to mount the new endpoint.
- Updates `cogs/terminal_cog.py` to save generated terminal images to a local directory (`terminal_images`) with unique filenames.
- Adds a base URL constant (`API_BASE_URL`) to `cogs/terminal_cog.py` for potential future use in generating image URLs.
