Fix: Destructure APP_TEMPLATES from app-templates module export

The module exports { APP_TEMPLATES, TEMPLATE_CATEGORIES, DIFFICULTY_LEVELS }
but catalog/wizard were receiving the wrapper object, not the array.

dashcaddy-api/src/app.js

@@ -625,14 +625,15 @@ async function createApp() {
   }));
 
   // DC-104: App catalog — browse curated templates
+  const { APP_TEMPLATES: templatesArray } = require('./docker/app-templates');
   apiRouter.use(catalogRoutes({
-    APP_TEMPLATES: require('./docker/app-templates'),
+    APP_TEMPLATES: templatesArray,
     asyncHandler: ctx.asyncHandler,
   }));
 
   // DC-105: Smart defaults wizard
   apiRouter.use(wizardRoutes({
-    APP_TEMPLATES: require('./docker/app-templates'),
+    APP_TEMPLATES: templatesArray,
     asyncHandler: ctx.asyncHandler,
   }));