Reduce MAX_CHUNK_SIZE from 64KB to 4KB to prevent large WebSocket frame issues

- Large WebSocket frames (131KB+) were causing SSL write failures during large file transfers
- Reduced MAX_CHUNK_SIZE from 65536 to 4096 bytes to create smaller, more manageable frames
- Smaller chunks improve network reliability and reduce timeout issues
- Hex-encoded 4KB binary data becomes 8KB frames, which is much more network-friendly

wssshtools/libwsssht/wssshlib.h

@@ -43,7 +43,7 @@
 #include <linux/route.h>
 
 #define BUFFER_SIZE 1048576
-#define MAX_CHUNK_SIZE 65536
+#define MAX_CHUNK_SIZE 4096
 #define DEFAULT_PORT 22
 
 // Global signal flag