fix: disable LiteLLM healthcheck due to missing curl

Healthcheck was failing because curl is not installed in the LiteLLM
container, causing Traefik to mark it as unhealthy and not route traffic.
Disabled healthcheck as Traefik doesn't require it for routing.

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

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

ai/compose.yaml

@@ -102,11 +102,7 @@ services:
     networks:
       - compose_network
     healthcheck:
-      test: ["CMD-SHELL", "curl -f http://localhost:4000/health || exit 1"]
+      disable: true
-      interval: 30s
-      timeout: 10s
-      retries: 3
-      start_period: 20s
     labels:
       - 'traefik.enable=${AI_TRAEFIK_ENABLED}'
       # HTTP to HTTPS redirect