Amnezia Android uses qUncompress which expects:
- 4-byte big-endian uncompressed length prefix
- zlib compressed data (gzcompress output)
Previously we used a custom 12-byte header (version, compressedLen, uncompressedLen)
which was incompatible with Qt's qUncompress.
This fix ensures X-Ray QR codes can be properly decoded by Amnezia VPN app.