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/requirements-soprano.txt

@@ -0,0 +1,52 @@
+# Soprano TTS Container Requirements (CUDA/Python 3.11.14)
+# pip==25.3
+# Generated from: .venv-cuda/bin/pip list --format=freeze
+#
+# Core dependencies
+fastapi==0.128.0
+uvicorn==0.40.0
+pyzmq==27.1.0
+numpy==2.4.1
+pydantic==2.12.5
+python-multipart==0.0.21
+
+# Audio processing
+sounddevice==0.5.3
+pydub==0.25.1
+
+# LMDeploy and dependencies
+lmdeploy==0.11.1
+transformers==4.57.5
+tokenizers==0.22.2
+huggingface-hub==0.36.0
+safetensors==0.7.0
+
+# Torch with CUDA 11.8 (installed separately via pip)
+# torch==2.7.1+cu118
+# torchaudio==2.7.1+cu118
+# torchvision==0.22.1+cu118
+
+# Supporting libraries
+accelerate==1.12.0
+sentencepiece==0.2.1
+protobuf==6.33.4
+tiktoken==0.12.0
+requests==2.32.5
+tqdm==4.67.1
+PyYAML==6.0.3
+Jinja2==3.1.6
+click==8.3.1
+psutil==7.2.1
+packaging==25.0
+filelock==3.20.3
+fsspec==2026.1.0
+regex==2026.1.14
+certifi==2026.1.4
+charset-normalizer==3.4.4
+urllib3==2.6.3
+idna==3.11
+
+# Additional dependencies for soprano
+einops==0.8.1
+peft==0.14.0
+scipy==1.17.0