webui: organize config page with subtabs

tests/test_http_api_contract.py

@@ -375,3 +375,29 @@ def test_embedded_webui_api_badge_labels_are_clear():
     assert "API Live" in source
     assert "API Error" in source
     assert 'textContent="Offline"' not in source
+
+
+def test_embedded_webui_config_page_is_grouped():
+    source = firmware_source()
+
+    assert "configGroupTitle" in source
+    assert "General" in source
+    assert "Home / Starlink WiFi" in source
+    assert "Relay Outputs" in source
+    assert "Temperature Assignment" in source
+    assert "BMS Config" in source
+    assert "Maintenance" in source
+
+
+def test_embedded_webui_config_subtabs():
+    source = firmware_source()
+
+    assert "function showConfigSubtab(name)" in source
+    assert "config-general" in source
+    assert "config-wifi" in source
+    assert "config-relays" in source
+    assert "config-temps" in source
+    assert "config-bms" in source
+    assert "config-maintenance" in source
+    assert "WiFi / AP" in source
+    assert "subtabbtn active" in source