fix(email): open settings after OAuth callback (#5803)

tests/test_email_oauth_settings_redirect.py

@@ -0,0 +1,19 @@
+"""Regression coverage for the settings UI after Google OAuth redirects."""
+
+from pathlib import Path
+
+
+_REPO = Path(__file__).resolve().parents[1]
+
+
+def test_oauth_redirect_uses_the_module_local_settings_api():
+    source = (_REPO / "static" / "js" / "settings.js").read_text(encoding="utf-8")
+    handler = source[
+        source.index("(function _handleOauthRedirect"):
+        source.index("const settingsModule =")
+    ]
+
+    assert "open('integrations');" in handler
+    assert "window.settingsModule" not in handler
+    assert "window.__odysseusAppStarted" not in handler
+    assert "document.addEventListener('DOMContentLoaded', _showResult, { once: true })" in handler