Fast_copy new release with new features

What's New

Performance

• Raw SSH tar streaming replaces SFTP for all remote transfers — 3-5x faster (4-5 MB/s on 100 Mbps LAN vs 1.2 MB/s with SFTP)
• Chunked 100 MB tar batches with streaming extraction — files extracted as data arrives, no temp files
• Per-byte progress for large files during tar extraction (e.g., a 4.8 GB file shows smooth progress instead of freezing)
• Threaded stdin/stdout on SSH channels to prevent deadlocks with large file lists
• Batched remote hashing — 5,000 files per SSH command to avoid channel timeouts on large repos (91k+ files)
• Remote link creation via batched Python script (5,000 links/batch) instead of individual shell commands

Security

• Hardened tar extraction — explicitly blocks symlinks, hard links, device files, FIFOs, null bytes in filenames
• 50 GB per-file size limit during tar extraction to prevent tar bomb attacks
• SSH host key warning with SHA256 fingerprint and MITM attack guidance
• SFTP-free manifest — read/write manifests via exec commands with SFTP fallback (works on servers with SFTP disabled, e.g., Synology NAS)

Windows

• Long path support (>260 characters) via \\?\ prefix for scan, copy, extract, verify, and hard link creation
• Path separator fix in verification — forward/backslash mismatch no longer causes false "MISSING" reports

Reliability

• Auth retry — prompts for password up to 3 times on failure; catches "No authentication methods available" errors
• Graceful Ctrl+C — clean "Interrupted." message, no tracebacks
• Remote space check walks parent directories when destination doesn't exist yet
• Incremental check fallback — if remote check fails (e.g., SFTP disabled), reconnects and copies all files instead of crashing

CLI

• Renamed SSH arguments for clarity: --ssh-src-port, --ssh-src-password, --ssh-dst-port, --ssh-dst-password
• Professional README with architecture docs, diagrams, and real-world benchmarks

Benchmarks

| Mode | Files | Data | Speed |
|------|-------|------|-------|
| Local → Local | 59,925 | 500.7 MB | 41.2 MB/s |
| Remote → Local | 91,669 | 509.8 MB | 619.5 KB/s |
| Local → Remote | 91,663 | 509.8 MB | 4.0 MB/s |
| Remote → Remote | 3 | 1.7 GB | 5.2 MB/s |

SHA-256 Checksums

8d31d13f45c81b80ea298a19f94c9ce74299623bbc4551159724803227e3c194  fast_copy-linux
d7b96de0a940a24a32ccc2da50047b2abf7ff36b5de8a8e7d5f5830857ca9b21  fast_copy-macos
fd5788cbecde3fab361eb07b14fb6f74c78d97bb1fd5456a560e4d6f697f86df  fast_copy-windows.exe
6ab6eec4e073209ba279999857decd1b757adae19014dc7d7c85d38b89f4d515  fast_copy.py