fix(recipe): prevent empty grid by removing preserveScroll from refresh triggers

Bug: when scrolling down on recipes page, any operation with
preserveScroll: true would fetch only page 1 data then restore
scroll position to beyond the loaded items, leaving the grid empty.

Fix:
- Remove preserveScroll: true from all 7 must-refresh trigger
  paths (filter, search, sort, import, settings reload, sync,
  rebuild cache, sidebar folder nav)
- Replace full list refresh with updateSingleItem() for repair
  and bulk missing-LoRA download operations
- Update tests to match new scroll-free behavior

static/js/managers/SettingsManager.js

@@ -2876,7 +2876,7 @@ export class SettingsManager {
             await resetAndReload(false);
         } else if (this.currentPage === 'recipes') {
             // Reload the recipes without updating folders
-            await window.recipeManager.loadRecipes({ preserveScroll: true });
+            await window.recipeManager.loadRecipes(true);
         } else if (this.currentPage === 'checkpoints') {
             // Reload the checkpoints without updating folders
             await resetAndReload(false);