Restructure: Move services from root to unified repo

Moved updated services from /home/sam/development/ root into aboutme_chat_demo/:
- knowledge_service/ (with ChromaDB, gitea_scraper, FastAPI)
- langgraph_service/ (with LangGraph agent orchestration)
- airflow/ (with DAGs for scheduled ingestion)

All services now in single repo location.
Modular docker-compose files per service maintained.
Removed duplicate nested directories.
Updated files reflect latest working versions.

langgraph_service/docker-compose.yml

@@ -0,0 +1,26 @@
+version: '3.8'
+
+services:
+  langgraph-service:
+    build: .
+    image: langgraph-service:latest
+    container_name: langgraph-service
+    ports:
+      - "8090:8090"
+    volumes:
+      # Only mount code files, not packages
+      - ./main.py:/app/code/main.py:ro
+      - ./supervisor_agent.py:/app/code/supervisor_agent.py:ro
+    environment:
+      - PYTHONUNBUFFERED=1
+      - PYTHONPATH=/app/packages
+      - OPENCODE_PASSWORD=${OPENCODE_PASSWORD:-sam4jo}
+      - KNOWLEDGE_SERVICE_URL=http://knowledge-service:8080
+    networks:
+      - ai-mesh
+    restart: unless-stopped
+
+networks:
+  ai-mesh:
+    external: true
+