Pick folders from a lazily loaded tree with find-by-name and typed paths, beside a plan showing
the books each organization mode would import, overlaps with other libraries, and folders no
library reads yet. New ManageLibraries /path routes walk folders within entry and time bounds.
Fix the scanner filing a disc-named library folder such as /mnt/disk1 under the folder above it,
and move books already filed there onto their primary file on the next scan.
Introduce a LIBRARY_BROWSE_ROOT environment variable (defaulting to the
current directory) to restrict directories users can browse and select when
setting up library paths. Add a PathPolicyService on the backend to enforce
path containment checks securely, and update the frontend FolderPickerModal
to prevent navigating above the configured browse root.
Closes#567
Introduces PathService.createDirectory with comprehensive path validation
to prevent directory traversal and symlink attacks. It validates parent paths
against a blocked list, ensures the parent is a real directory, and blocks
unsafe characters in folder names.
Filesystem errors like EEXIST and EACCES are mapped to standard HTTP
exceptions to provide clear feedback to the client.
Closes#332
neon