feat(docs): localize structured metadata and gate coverage

src/govoplan_docs/backend/api/v1/routes.py

@@ -17,6 +17,7 @@ from govoplan_core.core.modules import (
     ModuleManifest,
     NavItem,
     PermissionDefinition,
+    localized_documentation_metadata,
     user_workflow_scope_condition_issues,
 )
 from govoplan_core.core.registry import PlatformRegistry
@@ -1432,6 +1433,10 @@ def _documentation_topic_payload(
 ) -> dict[str, Any]:
     module_id = topic.source_module_id or source_module_id
     translation_locale, translation = _translation_for_locale(topic, locale)
+    structured_translation_locale = _structured_translation_locale(topic, locale)
+    localized_metadata = localized_documentation_metadata(
+        topic, structured_translation_locale
+    )
     kind = _documentation_topic_kind(topic)
     payload = {
         "id": topic.id,
@@ -1459,6 +1464,8 @@ def _documentation_topic_payload(
         "i18n_key": topic.i18n_key or topic.id,
         "locale": locale,
         "translation_locale": translation_locale,
+        "structured_translation_locale": structured_translation_locale,
+        "structured_translation_version": topic.structured_translation_version,
         "version": {
             "resolved": resolved_version,
             "minimum": topic.version_min,
@@ -1483,7 +1490,7 @@ def _documentation_topic_payload(
             _documentation_configuration_payload(configuration[key])
             for key in sorted(configuration)
         ],
-        "metadata": dict(topic.metadata),
+        "metadata": localized_metadata,
     }
     if documentation_type == "admin":
         return payload
@@ -1511,6 +1518,12 @@ def _documentation_topic_payload(
         "i18n_key": "",
         "locale": locale,
         "translation_locale": payload["translation_locale"],
+        "structured_translation_locale": payload[
+            "structured_translation_locale"
+        ],
+        "structured_translation_version": payload[
+            "structured_translation_version"
+        ],
         "conditions": [],
         "links": [
             _documentation_link_payload(link)
@@ -1521,7 +1534,7 @@ def _documentation_topic_payload(
         "unlocks": list(topic.unlocks),
         "configuration_keys": [],
         "configuration_states": [],
-        "metadata": _user_topic_metadata(kind, topic.metadata),
+        "metadata": _user_topic_metadata(kind, localized_metadata),
     }
 
 
@@ -1662,6 +1675,13 @@ def _translation_for_locale(topic: DocumentationTopic, locale: str) -> tuple[str
     return "source", {}
 
 
+def _structured_translation_locale(topic: DocumentationTopic, locale: str) -> str:
+    for candidate in _locale_candidates(locale):
+        if candidate in topic.structured_translations:
+            return candidate
+    return "source"
+
+
 def _locale_candidates(locale: str) -> tuple[str, ...]:
     normalized = _normalize_locale(locale)
     base = normalized.split("-", 1)[0]