Disable OpenAI API key validation for local vLLM endpoint

Open WebUI was validating API keys against OpenAI's servers.
For local vLLM backend, disable this validation.

cluster/applications/open-webui/deployment.yaml

@@ -51,6 +51,9 @@ spec:
               optional: false
         - name: OPENAI_MODEL_FALLBACK
           value: "Gemma-4-26B-A4B-it-AWQ"
+        # Disable OpenAI API key validation (we're using vLLM, not OpenAI)
+        - name: OPENAI_VALIDATE_ENDPOINT
+          value: "false"
         # Allow access from ingress
         - name: WEBUI_URL
           value: "https://body-wars.local.mk-labs.cloud"