chore: reset Presenton to clean installation

- Remove LiteLLM proxy configuration
- Reset to default single-container setup
- Clear all custom LLM and image provider settings
- Remove litellm-config.yaml
- Simple .env with minimal configuration

Service is now in clean state ready for fresh configuration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

opt/02-core/presenton/docker-compose.yml

@@ -1,39 +1,16 @@
 version: '3.8'
 
 services:
-  litellm-proxy:
-    image: ghcr.io/berriai/litellm:main-latest
-    container_name: litellm-proxy
-    restart: unless-stopped
-    networks:
-      - presenton-internal
-    volumes:
-      - ./litellm-config.yaml:/app/config.yaml
-    command: ["--config", "/app/config.yaml", "--host", "0.0.0.0", "--port", "4000"]
-    environment:
-      - LITELLM_MASTER_KEY=presenton-proxy-key-2025
-    deploy:
-      resources:
-        limits:
-          cpus: '1'
-          memory: 1G
-        reservations:
-          cpus: '0.5'
-          memory: 256M
-
   presenton:
     image: ghcr.io/presenton/presenton:latest
     container_name: presenton
     restart: unless-stopped
     networks:
       - traefik-public
-      - presenton-internal
     env_file:
       - .env
     volumes:
       - ./app_data:/app_data
-    depends_on:
-      - litellm-proxy
     deploy:
       resources:
         limits:
@@ -53,4 +30,3 @@ services:
 networks:
   traefik-public:
     external: true
-  presenton-internal: