add: absorb soprano_to_rvc as regular subdirectory

Voice conversion pipeline (Soprano TTS → RVC) with Docker support.
Previously tracked as bare gitlink; removed .git/ directories and
absorbed into main repo for unified tracking.

Includes: Soprano TTS, RVC WebUI integration, Docker configs,
WebSocket API, and benchmark scripts.
Updated .gitignore to exclude large model weights (*.pth, *.pt, *.onnx, *.index).
287 files (3.1GB of ML weights properly excluded via gitignore).

soprano_to_rvc/test_websocket.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""
+Quick WebSocket test - sends a few tokens and receives audio
+"""
+import asyncio
+import websockets
+import json
+
+async def quick_test():
+    uri = "ws://localhost:8765/ws/stream"
+    
+    print(f"Connecting to {uri}...")
+    async with websockets.connect(uri) as websocket:
+        print("✓ Connected!")
+        
+        # Send a simple sentence token by token
+        tokens = ["Hello", "!", " ", "This", " ", "is", " ", "a", " ", "test", "."]
+        
+        for token in tokens:
+            print(f"→ Sending: '{token}'")
+            await websocket.send(json.dumps({"token": token, "pitch_shift": 0}))
+            
+            # Try to receive audio (non-blocking)
+            try:
+                response = await asyncio.wait_for(websocket.recv(), timeout=5.0)  # Increased timeout
+                if isinstance(response, bytes):
+                    print(f"  ← Received {len(response)} bytes of audio")
+                else:
+                    print(f"  ← Received: {response}")
+            except asyncio.TimeoutError:
+                print(f"  (no response yet)")
+        
+        print("\n→ Flushing buffer...")
+        await websocket.send(json.dumps({"flush": True}))
+        
+        # Get remaining audio
+        try:
+            while True:
+                response = await asyncio.wait_for(websocket.recv(), timeout=10.0)  # Increased timeout
+                if isinstance(response, bytes):
+                    print(f"  ← Received {len(response)} bytes of audio (flush)")
+                else:
+                    print(f"  ← Received: {response}")
+        except asyncio.TimeoutError:
+            print("  (flush complete)")
+        
+        print("\n✓ Test complete!")
+
+if __name__ == "__main__":
+    asyncio.run(quick_test())