Backend MVP: FastAPI + Claude integration

Core components:
- FastAPI server with health endpoints
- AI client (Anthropic Claude integration)
- Context manager (loads company knowledge)
- Chat API (non-streaming and streaming)
- Requirements and environment setup

Ready to run: python backend/main.py

backend/.env.example

@@ -0,0 +1,21 @@
+# Grimlock Backend Configuration
+
+# API Keys
+ANTHROPIC_API_KEY=your-anthropic-api-key-here
+
+# Server Configuration
+HOST=0.0.0.0
+PORT=8000
+DEBUG=true
+
+# Context Configuration
+CONTEXT_PATH=/app/context
+REPOS_PATH=/app/repos
+
+# AI Configuration
+AI_MODEL=claude-sonnet-4-5-20250514
+AI_MAX_TOKENS=4096
+AI_TEMPERATURE=0.7
+
+# Logging
+LOG_LEVEL=INFO