feat(ai): disable Ollama API in WebUI, use LiteLLM only

ai/compose.yaml

@@ -38,6 +38,10 @@ services:
       OPENAI_API_BASE_URLS: http://litellm:4000
       OPENAI_API_KEYS: ${AI_LITELLM_API_KEY}
 
+      # Disable Ollama (we only use LiteLLM)
+      ENABLE_OLLAMA_API: false
+      OLLAMA_BASE_URLS: ""
+
       # WebUI configuration
       WEBUI_NAME: ${AI_WEBUI_NAME:-Pivoine AI}
       WEBUI_URL: https://${AI_TRAEFIK_HOST}