feat(plugins): show plugin logs on detail page via Docs/Logs tablist

Add a Logs tab beside Documentation on the plugin detail page, showing
the output a plugin prints through the standard Python logger (per the
wiki style guide). Logs are captured from the plugin's stderr by the
plugin runtime and fetched on demand.

- Bump langbot-plugin pin to 0.4.4 (adds GET_PLUGIN_LOGS action)
- plugin_connector/handler: get_plugin_logs RPC client
- HTTP route GET /api/v1/plugins/<author>/<name>/logs (limit + level)
- Frontend: wrap detail right panel in Docs/Logs Tabs; PluginLogs
  component with level filter, manual + 3s auto refresh, bottom-follow
- i18n: 7 new keys across all 8 locales

src/langbot/pkg/plugin/connector.py

@@ -689,6 +689,16 @@ class PluginRuntimeConnector(ManagedRuntimeConnector):
     async def get_plugin_readme(self, plugin_author: str, plugin_name: str, language: str = 'en') -> str:
         return await self.handler.get_plugin_readme(plugin_author, plugin_name, language)
 
+    async def get_plugin_logs(
+        self,
+        plugin_author: str,
+        plugin_name: str,
+        limit: int = 200,
+        level: str | None = None,
+    ) -> list[dict[str, Any]]:
+        # Not cached: logs are live and change constantly.
+        return await self.handler.get_plugin_logs(plugin_author, plugin_name, limit, level)
+
     @alru_cache(ttl=5 * 60)
     async def get_plugin_assets(self, plugin_author: str, plugin_name: str, filepath: str) -> dict[str, Any]:
         return await self.handler.get_plugin_assets(plugin_author, plugin_name, filepath)