Add ares-pull tool for downloading files from webOS devices

[mariotaku]

Summary

This PR introduces a new ares-pull command-line tool that enables users to download files and directories from webOS devices to their local machine via SFTP.

Key Changes

• New ares-pull binary: A command-line utility that mirrors the functionality of ares-push but in the opposite direction (device → host)
• SFTP-based file transfer: Leverages libssh-rs to establish SFTP connections and recursively pull files from remote devices
• Flexible path mapping: Implements intelligent destination path resolution:
  • Files map directly to the destination path
  • Trailing "/" on destination preserves the source's last path component
  • Directory contents are recursively copied
• Error handling options: Supports --ignore flag to continue on errors instead of stopping at first failure
• Device selection: Allows specifying a target device via --device flag or ARES_DEVICE environment variable
• Symlink handling: Safely skips symlinks during transfer with informative messages

Implementation Details

• Recursive directory traversal with proper handling of "." and ".." entries
• Parent directory creation for nested file structures
• Progress output showing source and destination paths during transfer
• Comprehensive unit tests for path resolution logic covering various edge cases
• Proper error conversion from libssh-rs errors to standard Rust IO errors

https://claude.ai/code/session_017vAGzSSYNcgdQzJRLWfX47