feat(10-02): add tender-radar module-loader whitelist entry + placeholder page

- MODULE_REGISTRY['tender-radar'] entry (mirrors cert-manager/dkv-fleet shape)
- minimal client-component placeholder page proving activation -> page-load path
- hardcoded German string is an intentional MVP stub; full i18n is CONFIG-03 (Phase 14)

apps/web/src/lib/module-loader.ts

@@ -47,6 +47,12 @@ export const MODULE_REGISTRY: Record<string, ModuleRegistryEntry> = {
       { ssr: false },
     ),
   },
+  'tender-radar': {
+    component: dynamic(
+      () => import('@/app/(portal)/modules/tender-radar/page'),
+      { ssr: false },
+    ),
+  },
 };
 
 /**