feat(planner): add remove meal with undo; fix RecipePicker badge for neutral delta

- MealActionSheet: new onremove prop + Entfernen button (guarded by #if)
- +page.svelte: handleRemoveMeal submits delete form, shows undo bar;
  undo re-adds via addSlot form; refactored handleUndo to undoCallback
  pattern; desktop day-detail panel also gets Entfernen button
- RecipePicker: only show green +delta badge when scoreDelta > 0;
  neutral (scoreDelta = 0) shows no badge instead of ⚠ Variationskonflikt
- Tests: page.test.ts remove-meal describe, RecipePicker neutral badge test

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

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

@@ -100,6 +100,7 @@
 	// UndoBar
 	let undoVisible = $state(false);
 	let undoMessage = $state('');
+	let undoCallback = $state<(() => void) | null>(null);
 
 	$effect(() => {
 		if (!activePickerDate || !weekPlan?.id) {
@@ -162,7 +163,33 @@
 
 	function handleUndo() {
 		undoVisible = false;
+		undoCallback?.();
+	}
+
+	async function handleRemoveMeal(slot: { id: string; slotDate: string; recipe: { id: string; name: string } | null }) {
+		// Capture primitive values immediately — slot may be a reactive proxy that
+		// becomes stale after the first await (tick flushes state + re-render).
+		const slotId = slot.id;
+		const slotDate = slot.slotDate;
+		const recipeName = slot.recipe?.name ?? '';
+		const recipeId = slot.recipe?.id ?? '';
+		if (!slotId || !recipeId) return;
+
+		actionSheetOpen = false;
+		undoCallback = async () => {
+			addPlanId = weekPlan!.id;
+			addSlotDate = slotDate;
+			addRecipeId = recipeId;
+			addRecipeName = recipeName;
+			await tick();
+			addSlotFormEl.requestSubmit();
+		};
+		delPlanId = weekPlan!.id;
+		delSlotId = slotId;
+		await tick();
 		deleteSlotFormEl.requestSubmit();
+		undoMessage = `${recipeName} entfernt`;
+		undoVisible = true;
 	}
 
 	async function handleSwapPick(recipeId: string, recipeName: string) {
@@ -315,12 +342,13 @@
 		/>
 	</BottomSheet>
 
-	<!-- Mobile: meal exists → action sheet (Swap / Cook / View / Cancel) -->
+	<!-- Mobile: meal exists → action sheet (Swap / Cook / View / Remove / Cancel) -->
 	<MealActionSheet
 		open={actionSheetOpen}
 		slot={selectedSlot}
 		onswap={() => { actionSheetOpen = false; swapSheetOpen = true; }}
 		oncancel={() => (actionSheetOpen = false)}
+		onremove={isPlanner && selectedSlot.id ? () => handleRemoveMeal(selectedSlot as any) : undefined}
 	/>
 
 	<!-- Mobile: swap suggestions sheet -->
@@ -530,6 +558,15 @@
 							>
 								Gericht tauschen
 							</button>
+							{#if detailSlot.id}
+								<button
+									type="button"
+									onclick={() => { handleRemoveMeal(detailSlot as any); panelState = { kind: 'idle' }; }}
+									class="block w-full rounded-[var(--radius-md)] border border-[var(--color-error,#d9534f)] px-3 py-2 text-center text-[13px] font-medium tracking-[0.04em] font-[var(--font-sans)] text-[var(--color-error,#d9534f)] hover:bg-[var(--color-surface)]"
+								>
+									Entfernen
+								</button>
+							{/if}
 						{/if}
 					</div>
 				{:else}
@@ -611,8 +648,10 @@
 			formData.set('recipeId', addRecipeId);
 			return async ({ result, update }) => {
 				if (result.type === 'success' && result.data?.success) {
+					const slotId = (result.data as any)?.slot?.id ?? '';
 					delPlanId = addPlanId;
-					delSlotId = (result.data as any)?.slot?.id ?? '';
+					delSlotId = slotId;
+					undoCallback = () => deleteSlotFormEl.requestSubmit();
 					undoMessage = `${addRecipeName} hinzugefügt`;
 					undoVisible = true;
 				}
@@ -639,6 +678,7 @@
 				if (result.type === 'success' && result.data?.success) {
 					delPlanId = updPlanId;
 					delSlotId = (result.data as any)?.slot?.id ?? '';
+					undoCallback = () => deleteSlotFormEl.requestSubmit();
 					undoMessage = `${updRecipeName} eingetragen`;
 					undoVisible = true;
 				}