fix(local): recognize unqualified hostnames as local endpoints (#9248)

Docker Compose service names (e.g. ollama, litellm, hermes-litellm)
are unqualified hostnames with no dots. These are always local — they
resolve via Docker DNS, /etc/hosts, or mDNS. Without this fix, the
stale stream timeout fires on local LLM proxies, causing infinite
reconnect loops.

Closes #7905

agent/model_metadata.py

@@ -441,6 +441,10 @@ def is_local_endpoint(base_url: str) -> bool:
     # Docker / Podman / Lima internal DNS names (e.g. host.docker.internal)
     if any(host.endswith(suffix) for suffix in _CONTAINER_LOCAL_SUFFIXES):
         return True
+    # Unqualified hostnames (no dots) are local by definition — Docker
+    # Compose service names, /etc/hosts entries, or mDNS names.
+    if host and "." not in host:
+        return True
     # RFC-1918 private ranges, link-local, and Tailscale CGNAT
     try:
         addr = ipaddress.ip_address(host)

tests/agent/test_local_stream_timeout.py

@@ -98,6 +98,16 @@ class TestIsLocalEndpoint:
     def test_container_dns_names(self, url):
         assert is_local_endpoint(url) is True
 
+    @pytest.mark.parametrize("url", [
+        "http://ollama:11434",
+        "http://litellm:4000/v1",
+        "http://hermes-litellm:8080",
+        "http://vllm:8000",
+    ])
+    def test_unqualified_docker_hostnames(self, url):
+        """Unqualified hostnames (no dots) are local — Docker Compose, /etc/hosts, etc."""
+        assert is_local_endpoint(url) is True
+
     @pytest.mark.parametrize("url", [
         "https://api.openai.com",
         "https://openrouter.ai/api",