feat: initial FastAPI boilerplate setup

Set up Webber - multi-agent AI development system with:

- Domain-based project structure (src/domains/, src/shared/)
- BaseController pattern with lazy router instantiation
- Pydantic Settings configuration with env file support
- Logger decorator with temporal benchmarking and trace IDs
- UserProvider singleton for request-scoped context
- Custom exception hierarchy
- Health endpoints (/, /health)

Dependencies (CVE checked 2026-01-09):
- FastAPI 0.128.0, Starlette 0.50.0, Uvicorn 0.40.0
- Pydantic 2.12.4, PydanticAI 1.40.0
- All packages at latest safe versions

Placeholder domains for future implementation:
- agents/ (explore, plan, task)
- tools/ (file, shell, search)
- auth/ (tatlock integration)

Port: 8086 (per CONTAINERS.md allocation)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,31 @@
+# Webber Configuration
+# Copy to .env and customize
+
+# Application
+DEBUG=true
+LOG_LEVEL=DEBUG
+
+# Server
+HOST=0.0.0.0
+PORT=8086
+
+# CORS (comma-separated)
+CORS_ORIGINS=["http://localhost:3000","http://localhost:8080"]
+
+# LLM - Ollama (tower-of-joy)
+OLLAMA_URL=http://192.168.86.149:11434
+OLLAMA_AGENT_MODEL=mistral-nemo-large:latest
+OLLAMA_EMBED_MODEL=nomic-embed-text:latest
+
+# Auth - Tatlock integration (optional)
+# TATLOCK_API_URL=http://192.168.86.149:8000
+# INTERNAL_API_KEY=your-internal-key
+
+# Tool execution
+TOOL_TIMEOUT_SECONDS=120
+SANDBOX_ENABLED=true
+# ALLOWED_PATHS=["/home/user/projects","/tmp/webber"]
+
+# Sessions
+SESSION_TTL_HOURS=24
+MAX_CONTEXT_TOKENS=128000