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/soprano/pyproject.toml

@@ -0,0 +1,43 @@
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "soprano-tts"
+version = "0.1.0"
+authors = [
+  { name="ekwek1", email="eugene.kwek.1@gmail.com" },
+]
+description = "Soprano: Instant, Ultra‑Realistic Text‑to‑Speech"
+readme = "README.md"
+requires-python = ">=3.10"
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "Operating System :: OS Independent",
+]
+dependencies = [
+  "accelerate",
+  "fastapi",
+  "gradio",
+  "huggingface_hub",
+  "numpy",
+  "scipy",
+  "sounddevice",
+  "torch>=2.1.0",
+  "transformers>=4.51.0",
+  "unidecode",
+  "uvicorn",
+  "inflect"
+]
+license = {file = "LICENSE"}
+
+[project.optional-dependencies]
+lmdeploy = ["lmdeploy"]
+
+[project.urls]
+Homepage = "https://github.com/ekwek1/soprano"
+Issues = "https://github.com/ekwek1/soprano/issues"
+
+[project.scripts]
+soprano = "soprano.cli:main"
+soprano-webui = "soprano.webui:main"