Design an in-memory file system with limits

Design and implement an in-memory hierarchical file system. Requirements:

1. addFile(String path): Given an absolute path like "path/to/somewhere/file.txt", create intermediate folders as needed and store a file at the leaf.
2. get(String path): Given a directory path, return the names of its immediate children; for example, if the only child of "path/to/somewhere" is "file.txt", return "file.txt"; if the only child of "path/to" is the subfolder "somewhere", return "somewhere". Constraints: a) Capacity—each directory may contain at most 5 entries (files + folders); if an insertion would cause a directory to exceed 5 entries at that level, reject the operation. b) Auto-rename on duplicates—within the same directory, if a file name already exists, automatically rename the new file using OS-style suffixing: base ( 1).ext, base ( 2).ext, ... Maintain counters per base name. Example sequence: add("file.txt"), add("file.txt"), add("file ( 1).txt") should result in files named "file.txt", "file ( 1).txt", and "file ( 1)( 1).txt". Clarify behaviors and edge cases (invalid paths, conflicts where a file exists where a folder is required, idempotency, case sensitivity), and provide time/space complexity.