feat: Chatbot-Workflows mit Ollama-Memory und Session-Management

- docker-compose: extra_hosts für host.docker.internal (Ollama-Zugang)
- ollama-chatbot: Gesprächsverlauf per session_id in PostgreSQL
- ollama-chat-cleanup: stündliche TTL-Bereinigung (2h Inaktivität)
- ollama-chat-delete: DELETE /webhook/chat-session Endpoint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

compose/docker-compose.yml

@@ -75,6 +75,8 @@ services:
       - ../data/n8n:/home/node/.n8n
       - ../local-files:/files
       - ../imports:/imports
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     depends_on:
       postgres:
         condition: service_healthy
@@ -108,6 +110,8 @@ services:
     volumes:
       - ../data/n8n:/home/node/.n8n
       - ../local-files:/files
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     depends_on:
       - n8n
     networks: