fix(dash): use reachable host in footer API docs link (#1354)

link to EOS API using reachable host

tests/test_footer.py

@@ -0,0 +1,28 @@
+"""Regression tests for browser-facing links in the EOSdash footer."""
+
+from unittest.mock import patch
+
+import pytest
+from bs4 import BeautifulSoup
+from fasthtml.common import to_xml
+
+from akkudoktoreos.server.dash.footer import Footer
+
+
+@pytest.mark.parametrize(
+    "bind_host,request_host,expected_host",
+    [
+        ("0.0.0.0", "energy.example.com", "energy.example.com"),
+        ("::", "2001:db8::1", "[2001:db8::1]"),
+        ("api.example.com", "dashboard.example.com", "api.example.com"),
+    ],
+)
+def test_footer_docs_link_uses_reachable_host(bind_host, request_host, expected_host):
+    """The browser link must not expose a wildcard bind address."""
+    with patch("akkudoktoreos.server.dash.footer.get_alive", return_value="alive") as health:
+        footer = BeautifulSoup(to_xml(Footer(bind_host, 8503, request_host)), "html.parser")
+
+    link = footer.find("a", href=f"http://{expected_host}:8503/docs")
+    assert link is not None
+    assert link.get_text(strip=True) == f"EOS {expected_host}:8503"
+    health.assert_called_once_with(bind_host, 8503)