Feature: Add Extended Metadata Support and JSON/CSV Output

[djdarcy]

Background:
Currently, listall.py only stores file/directory paths plus a minimal date-based sort for files. We can't easily sort subdirectories by date or output file size, permissions, etc. It was suggested to add richer data support, akin to a ls -lR or a CSV/JSON with all relevant metadata.

Proposal:

1. During the collect_files() phase, gather os.stat(...) for each directory and file, storing:
   • Modified time (mtime)
   • Size
   • Possibly creation time (ctime) or permissions
   • Permissions
   • etc
2. Store them in a data structure like:

   {
     "/abs/path/to/dir": {
       "mtime": ...,
       "files": [
         { "path": file_path, "mtime": ..., "size": ..., ... },
         ...
       ]
     },
     ...
   }