fix(infra): ml-serving LITELLM_URL default → host.docker.internal:4000

Inside the container, llm.alogins.net times out (public-DNS route, not the
loopback path Caddy listens on). host.docker.internal:4000 reaches the Agap
LiteLLM directly and is equivalent for dev. Prod deploys override via env.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

infra/docker/docker-compose.yml

@@ -65,7 +65,7 @@ services:
     profiles: [full]
     env_file: ../../.env.local
     environment:
-      LITELLM_URL: ${LITELLM_URL:-https://llm.alogins.net}
+      LITELLM_URL: ${LITELLM_URL:-http://host.docker.internal:4000}
       OLLAMA_URL: ${OLLAMA_URL:-http://host.docker.internal:11434}
     extra_hosts:
       - "host.docker.internal:host-gateway"