Returns a path to a neuroatlas-specific cache directory. If the directory (or a specified subdirectory) doesn't exist, it will be created. This function uses `tools::R_user_dir` to ensure a user-specific, OS-appropriate cache location.
Arguments
- subdir
Optional character string. If provided, a subdirectory named `subdir` will be created/used within the main neuroatlas cache directory.
- create
Logical. If `TRUE` (default), create the directory if it does not exist. If `FALSE`, return the path without creating it (for read-only lookups that must not write to the user's home cache).