feat: add initial Hold Slayer AI telephony gateway implementation

Complete project scaffolding and core implementation of an AI-powered
telephony system that calls companies, navigates IVR menus, waits on
hold, and transfers to the user when a human answers.

Key components:
- FastAPI server with REST API, WebSocket, and MCP (SSE) interfaces
- SIP/VoIP call management via PJSUA2 with RTP audio streaming
- LLM-powered IVR navigation using OpenAI/Anthropic with tool calling
- Hold detection service combining audio analysis and silence detection
- Real-time STT (Whisper/Deepgram) and TTS (OpenAI/Piper) pipelines
- Call recording with per-channel and mixed audio capture
- Event bus (asyncio pub/sub) for real-time client updates
- Web dashboard with live call monitoring
- SQLite persistence via SQLAlchemy with call history and analytics
- Notification support (email, SMS, webhook, desktop)
- Docker Compose deployment with Opal VoIP and Opal Media containers
- Comprehensive test suite with unit, integration, and E2E tests
- Simplified .gitignore and full project documentation in README

pyproject.toml

@@ -0,0 +1,71 @@
+[project]
+name = "hold-slayer"
+version = "0.1.0"
+description = "AI PSTN Gateway - Hold Slayer: Navigate IVRs, wait on hold, connect you when a human answers"
+readme = "README.md"
+requires-python = ">=3.12"
+license = "MIT"
+authors = [
+    {name = "Robert"},
+]
+
+dependencies = [
+    # Web framework
+    "fastapi>=0.115.0",
+    "uvicorn[standard]>=0.32.0",
+    "websockets>=13.0",
+    
+    # Database
+    "sqlalchemy[asyncio]>=2.0.36",
+    "asyncpg>=0.30.0",
+    "alembic>=1.14.0",
+    
+    # Settings & validation
+    "pydantic>=2.10.0",
+    "pydantic-settings>=2.6.0",
+    
+    # SIP signaling
+    "sippy>=1.2.0",
+    
+    # Audio analysis
+    "numpy>=1.26.0",
+    "librosa>=0.10.0",
+    "soundfile>=0.12.0",
+    
+    # HTTP client (for Speaches STT)
+    "httpx>=0.28.0",
+    
+    # MCP server
+    "fastmcp>=2.0.0",
+    
+    # Utilities
+    "python-slugify>=8.0.0",
+    "python-multipart>=0.0.12",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0.0",
+    "pytest-asyncio>=0.24.0",
+    "pytest-cov>=6.0.0",
+    "httpx>=0.28.0",
+    "ruff>=0.8.0",
+]
+
+[tool.setuptools.packages.find]
+include = ["api*", "core*", "db*", "models*", "services*", "mcp_server*"]
+
+[build-system]
+requires = ["setuptools>=75.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+
+[tool.ruff]
+target-version = "py312"
+line-length = 100
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "N", "W", "UP"]