feat: show optional serivce description before payment

tests/test_admin_settings_manifest_i18n.py

@@ -16,6 +16,12 @@ SUPPORT_RELATED_SETTINGS = (
     "SUPPORT_TICKET_RATE_LIMIT_PER_HOUR",
 )
 
+SUBSCRIPTION_PURCHASE_DESCRIPTION_SETTINGS = (
+    "SUBSCRIPTION_PURCHASE_DESCRIPTION_ENABLED",
+    "SUBSCRIPTION_PURCHASE_DESCRIPTION_RU",
+    "SUBSCRIPTION_PURCHASE_DESCRIPTION_EN",
+)
+
 
 def _manifest_by_key() -> dict[str, dict]:
     return {item["key"]: item for item in manifest_payload()}
@@ -50,3 +56,15 @@ def test_support_settings_i18n_keys_exist_in_admin_locales():
             field = manifest[setting_key]
             assert field["i18n_label_key"] in messages
             assert field["i18n_description_key"] in messages
+
+
+def test_subscription_purchase_description_settings_i18n_keys_exist():
+    manifest = _manifest_by_key()
+
+    for language in ("ru", "en"):
+        messages = _locale(language)
+        for setting_key in SUBSCRIPTION_PURCHASE_DESCRIPTION_SETTINGS:
+            field = manifest[setting_key]
+            assert field["section"] == "pricing"
+            assert field["i18n_label_key"] in messages
+            assert field["i18n_description_key"] in messages