This commit introduces the capability to upload and serve images.
A new `image` feature module has been added to the backend, following the existing clean architecture pattern.
- Implements `POST /image/upload` for uploading image files.
- Implements `GET /image/{id}` for retrieving an image by its ID.
- Adds a new `image` table to the database to store image metadata.
- Image data is stored in the file system. The path can be configured via the `STORAGE_PATH` environment variable.
