AssetManager 0.5.5.61

Standard image library path and upload workflow

Clarified that the persistent standard image library lives in ./data/image-library on the Docker host.
The bind mount exposes that same directory at /app/app/static/img/library inside the application container; this is not a second copy.
Added explicit STANDARD_IMAGE_DIR configuration and startup creation/logging of the active library directory.
Removed the direct per-record image upload controls from asset and category forms. New images are added to the shared library and can then be reused.
Existing legacy /static/uploads/... references remain supported for backward compatibility.
Documentation now explains that adding a new bind mount requires recreating the container, not only restarting it.