fix: handle text+bytes in terminal WS; mkdir -p before SFTP upload; robust conda path detection

backend/main.py

@@ -1,4 +1,4 @@
-import asyncio
+import asyncio
 import json
 import os
 import tempfile
@@ -368,8 +368,11 @@ async def ws_terminal(websocket: WebSocket):
         async def ws_to_ssh():
             try:
                 while True:
-                    data = await websocket.receive_bytes()
-                    channel.send(data)
+                    msg = await websocket.receive()
+                    if "bytes" in msg and msg["bytes"]:
+                        channel.send(msg["bytes"])
+                    elif "text" in msg and msg["text"]:
+                        channel.send(msg["text"].encode())
             except WebSocketDisconnect:
                 pass