feat(ui): add left/right arrow buttons to PageShell drag bar

Arrow buttons appear on hover at the left/right edges of the drag bar
to quickly reorder pages without dragging. Hidden when the page is
already first (no left arrow) or last (no right arrow).

- PageShell: onMoveLeft/onMoveRight props, CaretLeft/CaretRight icons
- AppPage: pass through move callbacks
- +page.svelte: handleMoveLeft/handleMoveRight with array swap + persist

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/manacore/apps/web/src/lib/components/page-carousel/PageShell.svelte

@@ -5,7 +5,15 @@
 -->
 <script lang="ts">
 	import { _ } from 'svelte-i18n';
-	import { X, Minus, DotsSixVertical, CornersOut, CornersIn } from '@manacore/shared-icons';
+	import {
+		X,
+		Minus,
+		DotsSixVertical,
+		CornersOut,
+		CornersIn,
+		CaretLeft,
+		CaretRight,
+	} from '@manacore/shared-icons';
 	import type { Snippet, Component } from 'svelte';
 
 	interface Props {
@@ -16,6 +24,8 @@
 		onMinimize?: () => void;
 		onMaximize?: () => void;
 		onResize?: (widthPx: number, heightPx?: number) => void;
+		onMoveLeft?: () => void;
+		onMoveRight?: () => void;
 		// Default header
 		title?: string;
 		color?: string;
@@ -35,6 +45,8 @@
 		onMinimize,
 		onMaximize,
 		onResize,
+		onMoveLeft,
+		onMoveRight,
 		title = '',
 		color = '#6B7280',
 		icon: IconComponent,
@@ -114,7 +126,33 @@
 		: ''}"
 >
 	<div class="drag-handle-bar" draggable="true">
+		{#if onMoveLeft}
+			<button
+				class="move-btn move-left"
+				onclick={(e) => {
+					e.stopPropagation();
+					onMoveLeft();
+				}}
+				draggable="false"
+				title="Nach links"
+			>
+				<CaretLeft size={12} />
+			</button>
+		{/if}
 		<span class="drag-handle-icon"><DotsSixVertical size={14} /></span>
+		{#if onMoveRight}
+			<button
+				class="move-btn move-right"
+				onclick={(e) => {
+					e.stopPropagation();
+					onMoveRight();
+				}}
+				draggable="false"
+				title="Nach rechts"
+			>
+				<CaretRight size={12} />
+			</button>
+		{/if}
 	</div>
 
 	<!-- Header -->
@@ -243,6 +281,7 @@
 	}
 
 	.drag-handle-bar {
+		position: relative;
 		display: flex;
 		justify-content: center;
 		align-items: center;
@@ -269,6 +308,46 @@
 	:global(.dark) .drag-handle-bar:active {
 		background: rgba(255, 255, 255, 0.08);
 	}
+	.move-btn {
+		position: absolute;
+		top: 50%;
+		transform: translateY(-50%);
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		width: 18px;
+		height: 18px;
+		border: none;
+		border-radius: 50%;
+		background: transparent;
+		color: #d1d5db;
+		cursor: pointer;
+		opacity: 0;
+		transition:
+			opacity 0.15s,
+			color 0.15s,
+			background 0.15s;
+	}
+	.drag-handle-bar:hover .move-btn {
+		opacity: 1;
+	}
+	.move-btn:hover {
+		color: #6b7280;
+		background: rgba(0, 0, 0, 0.06);
+	}
+	.move-left {
+		left: 0.5rem;
+	}
+	.move-right {
+		right: 0.5rem;
+	}
+	:global(.dark) .move-btn {
+		color: #3f3b38;
+	}
+	:global(.dark) .move-btn:hover {
+		color: #9ca3af;
+		background: rgba(255, 255, 255, 0.08);
+	}
 	.drag-handle-icon {
 		display: flex;
 		align-items: center;

apps/manacore/apps/web/src/lib/components/workbench/AppPage.svelte

@@ -29,6 +29,8 @@
 		onMinimize?: () => void;
 		onMaximize?: () => void;
 		onResize?: (widthPx: number, heightPx?: number) => void;
+		onMoveLeft?: () => void;
+		onMoveRight?: () => void;
 	}
 
 	let {
@@ -40,6 +42,8 @@
 		onMinimize,
 		onMaximize,
 		onResize,
+		onMoveLeft,
+		onMoveRight,
 	}: Props = $props();
 
 	let appEntry = $derived(getAppEntry(appId));
@@ -203,6 +207,8 @@
 		{onMinimize}
 		{onMaximize}
 		{onResize}
+		{onMoveLeft}
+		{onMoveRight}
 	>
 		{#if loadError}
 			<div class="load-state">

apps/manacore/apps/web/src/routes/(app)/+page.svelte

@@ -135,6 +135,24 @@
 		persistState();
 	}
 
+	function handleMoveLeft(id: string) {
+		const idx = openApps.findIndex((a) => a.appId === id);
+		if (idx <= 0) return;
+		const apps = [...openApps];
+		[apps[idx - 1], apps[idx]] = [apps[idx], apps[idx - 1]];
+		openApps = apps;
+		persistState();
+	}
+
+	function handleMoveRight(id: string) {
+		const idx = openApps.findIndex((a) => a.appId === id);
+		if (idx === -1 || idx >= openApps.length - 1) return;
+		const apps = [...openApps];
+		[apps[idx], apps[idx + 1]] = [apps[idx + 1], apps[idx]];
+		openApps = apps;
+		persistState();
+	}
+
 	function handleReorder(fromId: string, toId: string) {
 		const fromIdx = openApps.findIndex((a) => a.appId === fromId);
 		const toIdx = openApps.findIndex((a) => a.appId === toId);
@@ -166,6 +184,7 @@
 		addLabel="App hinzufügen"
 	>
 		{#snippet page(p)}
+			{@const idx = openApps.findIndex((a) => a.appId === p.id)}
 			<AppPage
 				appId={p.id}
 				widthPx={p.widthPx}
@@ -175,6 +194,8 @@
 				onMinimize={() => handleMinimizeApp(p.id)}
 				onMaximize={() => handleMaximizeApp(p.id)}
 				onResize={(w, h) => handleResize(p.id, w, h)}
+				onMoveLeft={idx > 0 ? () => handleMoveLeft(p.id) : undefined}
+				onMoveRight={idx < openApps.length - 1 ? () => handleMoveRight(p.id) : undefined}
 			/>
 		{/snippet}
 		{#snippet picker()}