feat(planner): add isLoading prop to SwapSuggestionList — disables Pick buttons during PATCH

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/routes/(app)/planner/+page.svelte

@@ -61,6 +61,7 @@
 	let pickerOpen = $state(false);
 	let actionSheetOpen = $state(false);
 	let swapSheetOpen = $state(false);
+	let swapLoading = $state(false);
 
 	// Recipes already in any slot this week — used for ⚠ overlap warnings
 	let currentWeekRecipeIds = $derived(
@@ -139,8 +140,10 @@
 	}
 
 	async function handleSwapPick(recipeId: string, recipeName: string) {
-		swapSheetOpen = false;
+		swapLoading = true;
 		await handleRecipePick(recipeId, recipeName);
+		swapSheetOpen = false;
+		swapLoading = false;
 	}
 
 	function closePanelToIdle() {
@@ -306,6 +309,7 @@
 				replacingMeta={replacingMeta || undefined}
 				recipes={sortedRecipes}
 				{currentWeekRecipeIds}
+				isLoading={swapLoading}
 				onpick={handleSwapPick}
 				oncancel={() => (swapSheetOpen = false)}
 			/>