Initial commit: Multi-service AI agent system

- Frontend: Vite + React + TypeScript chat interface
- Backend: FastAPI gateway with LangGraph routing
- Knowledge Service: ChromaDB RAG with Gitea scraper
- LangGraph Service: Multi-agent orchestration
- Airflow: Scheduled Gitea ingestion DAG
- Documentation: Complete plan and implementation guides

Architecture:
- Modular Docker Compose per service
- External ai-mesh network for communication
- Fast rebuilds with /app/packages pattern
- Intelligent agent routing (no hardcoded keywords)

Services:
- Frontend (5173): React chat UI
- Chat Gateway (8000): FastAPI entry point
- LangGraph (8090): Agent orchestration
- Knowledge (8080): ChromaDB RAG
- Airflow (8081): Scheduled ingestion
- PostgreSQL (5432): Chat history

Excludes: node_modules, .venv, chroma_db, logs, .env files
Includes: All source code, configs, docs, docker files

backend/main.py.new

@@ -0,0 +1,49 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from pydantic import BaseModel
+import httpx
+import logging
+import sys
+import traceback
+import os
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s", handlers=[logging.StreamHandler(sys.stdout)])
+logger = logging.getLogger(__name__)
+
+app = FastAPI()
+app.add_middleware(CORSMiddleware, allow_origins=["*"], allow_credentials=True, allow_methods=["*"], allow_headers=["*"])
+
+class MessageRequest(BaseModel):
+    message: str
+
+LANGGRAPH_URL = os.getenv("LANGGRAPH_URL", "http://langgraph-service:8090")
+
+@app.post("/chat")
+async def chat(request: MessageRequest):
+    """Updated chat endpoint that routes through LangGraph Supervisor."""
+    logger.info(f"Gateway: Received message: {request.message}")
+    
+    try:
+        # Call LangGraph Supervisor instead of direct brain
+        async with httpx.AsyncClient(timeout=httpx.Timeout(60.0, connect=10.0)) as client:
+            response = await client.post(
+                f"{LANGGRAPH_URL}/query",
+                json={"query": request.message}
+            )
+            
+            if response.status_code == 200:
+                result = response.json()
+                logger.info(f"Gateway: Response from {result.get('agent_used', 'unknown')} agent")
+                return {"response": result["response"]}
+            else:
+                logger.error(f"Gateway: LangGraph error {response.status_code}")
+                return {"response": "Error: Orchestration service unavailable"}
+                
+    except Exception as e:
+        logger.error(f"Gateway: Error routing through LangGraph: {traceback.format_exc()}")
+        return {"response": "Error: Unable to process your request at this time."}
+
+@app.get("/health")
+async def health():
+    return {"status": "healthy", "service": "chat-gateway"}
+