feat: translate STUDIO_BASE_URL to cmsBaseUrl in frontend site config

Maps the legacy STUDIO_BASE_URL key to the optional frontend-base
cmsBaseUrl field so it surfaces at the top level of FrontendSiteConfigView
instead of falling through to commonAppConfig.

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

Author: arbrandes

lms/djangoapps/mfe_config_api/tests/test_views.py

@@ -457,13 +457,16 @@ def side_effect(key, default=None):
         response = self.client.get(self.url)
         data = response.json()
 
-        # Site-level key translated to top level
+        common = data["commonAppConfig"]
+        # Site-level keys are translated to top level
         self.assertEqual(data["lmsBaseUrl"], "https://courses.example.com")  # noqa: PT009
+        self.assertEqual(data["cmsBaseUrl"], "https://studio.example.com")  # noqa: PT009
+        # Site-level keys translated to top level don't appear in commonAppConfig
+        self.assertNotIn("LMS_BASE_URL", common)  # noqa: PT009
+        self.assertNotIn("STUDIO_BASE_URL", common)  # noqa: PT009
         # Unmapped MFE_CONFIG keys appear in commonAppConfig (not at the top level)
         self.assertNotIn("CREDENTIALS_BASE_URL", data)  # noqa: PT009
-        common = data["commonAppConfig"]
         self.assertEqual(common["CREDENTIALS_BASE_URL"], "https://credentials.example.com")  # noqa: PT009
-        self.assertEqual(common["STUDIO_BASE_URL"], "https://studio.example.com")  # noqa: PT009
         # Legacy config keys also appear in commonAppConfig
         for legacy_key in default_legacy_config:
             self.assertIn(legacy_key, common)  # noqa: PT009
@@ -609,12 +612,13 @@ def side_effect(key, default=None):
         response = self.client.get(self.url)
         data = response.json()
 
-        # Site-level key is promoted to the top level
+        # Site-level keys are promoted to the top level
         self.assertEqual(data["lmsBaseUrl"], "https://courses.example.com")  # noqa: PT009
+        self.assertEqual(data["cmsBaseUrl"], "https://studio.example.com")  # noqa: PT009
         # Unmapped keys are preserved in commonAppConfig
         common = data["commonAppConfig"]
         self.assertEqual(common["CREDENTIALS_BASE_URL"], "https://credentials.example.com")  # noqa: PT009
-        self.assertEqual(common["STUDIO_BASE_URL"], "https://studio.example.com")  # noqa: PT009
+        self.assertNotIn("STUDIO_BASE_URL", common)  # noqa: PT009
 
     @patch("lms.djangoapps.mfe_config_api.views.get_legacy_config_overrides", return_value={})
     @patch("lms.djangoapps.mfe_config_api.views.configuration_helpers")

lms/djangoapps/mfe_config_api/views.py

@@ -30,6 +30,7 @@
     "LOGIN_URL": "loginUrl",
     "LOGOUT_URL": "logoutUrl",
     # OptionalSiteConfig
+    "STUDIO_BASE_URL": "cmsBaseUrl",
     "LOGO_URL": "headerLogoImageUrl",
     "ACCESS_TOKEN_COOKIE_NAME": "accessTokenCookieName",
     "LANGUAGE_PREFERENCE_COOKIE_NAME": "languagePreferenceCookieName",