feat(manacore, shared-ui): integrate cross-type DnD into unified app

- Shared TagStrip: add dragSource on tag pills + passiveDropZone for item→tag
  drops. New onTagDrop and dropAccepts props. DnD CSS for hover/success states.
- Unified app layout: add DragPreview, context-based tagDropHandler so child
  pages can register their own drop logic.
- Todo module: add updateLabels() to tasks store (with metadata merge).
- Todo page: add dropTarget on task items, tag badge display via getTaskTags(),
  register tagDropHandler for passive task→tag drops.

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

apps/manacore/apps/web/src/lib/modules/todo/stores/tasks.svelte.ts

@@ -110,6 +110,15 @@ export const tasksStore = {
 		});
 	},
 
+	async updateLabels(id: string, labelIds: string[]) {
+		const existing = await taskTable.get(id);
+		const existingMeta = (existing?.metadata as Record<string, unknown>) ?? {};
+		await taskTable.update(id, {
+			metadata: { ...existingMeta, labelIds },
+			updatedAt: new Date().toISOString(),
+		});
+	},
+
 	async reorderTasks(taskIds: string[]) {
 		for (let i = 0; i < taskIds.length; i++) {
 			await taskTable.update(taskIds[i], {

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

@@ -2,11 +2,11 @@
 	import { goto } from '$app/navigation';
 	import { page } from '$app/stores';
 	import type { Snippet } from 'svelte';
-	import { onMount } from 'svelte';
+	import { onMount, setContext } from 'svelte';
 	import KeyboardShortcutsModal from '$lib/components/KeyboardShortcutsModal.svelte';
 	import SessionWarning from '$lib/components/SessionWarning.svelte';
 	import { locale } from 'svelte-i18n';
-	import { PillNavigation, TagStrip } from '@manacore/shared-ui';
+	import { PillNavigation, TagStrip, DragPreview, ActionZone } from '@manacore/shared-ui';
 	import type { PillNavItem, PillDropdownItem, SpotlightAction } from '@manacore/shared-ui';
 	import { tagLocalStore, tagMutations, useAllTags } from '$lib/stores/tags.svelte';
 	import { linkLocalStore, linkMutations } from '@manacore/shared-links';
@@ -110,6 +110,19 @@
 		isTagStripVisible = !isTagStripVisible;
 	}
 
+	// DnD: tag drop handler — set by child pages via context
+	import type { DragPayload } from '@manacore/shared-ui/dnd';
+
+	let tagDropHandler = $state<((tagId: string, payload: DragPayload) => void) | null>(null);
+	setContext('tagDropHandler', {
+		set(handler: (tagId: string, payload: DragPayload) => void) {
+			tagDropHandler = handler;
+		},
+		clear() {
+			tagDropHandler = null;
+		},
+	});
+
 	// Navigation items for ManaCore
 	const baseNavItems: PillNavItem[] = [
 		{ href: '/home', label: 'Home', icon: 'home' },
@@ -353,11 +366,15 @@
 				selectedIds={[]}
 				onToggle={() => {}}
 				onClear={() => {}}
+				onTagDrop={tagDropHandler ?? undefined}
 				managementHref="/tags"
 				loading={allTags.loading}
 			/>
 		{/if}
 
+		<!-- DnD: floating preview + action zones -->
+		<DragPreview />
+
 		<!-- Main content -->
 		<main class="pb-24">
 			<div class="mx-auto max-w-7xl px-4 py-8 sm:px-6 lg:px-8">

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

@@ -1,6 +1,10 @@
 <script lang="ts">
 	import { getContext } from 'svelte';
 	import type { Observable } from 'dexie';
+	import { dropTarget } from '@manacore/shared-ui/dnd';
+	import type { DragPayload, TagDragData } from '@manacore/shared-ui/dnd';
+	import { useAllTags } from '$lib/stores/tags.svelte';
+	import { onMount } from 'svelte';
 	import {
 		type Task,
 		type LocalLabel,
@@ -8,6 +12,7 @@
 		type LocalTodoProject,
 		type TaskPriority,
 		tasksStore,
+		taskTable,
 		viewStore,
 		filterIncomplete,
 		filterCompleted,
@@ -66,6 +71,15 @@
 		return () => sub.unsubscribe();
 	});
 
+	// Global tags for resolving labelIds to names/colors
+	const globalTags = useAllTags();
+	const tagMap = $derived(new Map((globalTags.value ?? []).map((t) => [t.id, t])));
+
+	function getTaskTags(task: Task) {
+		const ids: string[] = (task.metadata as { labelIds?: string[] })?.labelIds ?? [];
+		return ids.map((id) => tagMap.get(id)).filter((t): t is NonNullable<typeof t> => t != null);
+	}
+
 	// Task stats
 	let stats = $derived(getTaskStats(allTasks));
 
@@ -114,6 +128,42 @@
 		await tasksStore.deleteTask(task.id);
 	}
 
+	// ── DnD: register tag drop handler for passive drops (task→tag in TagStrip)
+	const tagDropCtx = getContext<{
+		set: (handler: (tagId: string, payload: DragPayload) => void) => void;
+		clear: () => void;
+	}>('tagDropHandler');
+
+	onMount(() => {
+		tagDropCtx?.set(async (tagId: string, payload: DragPayload) => {
+			const taskData = payload.data as TagDragData;
+			const task = await taskTable.get(taskData.id);
+			if (!task) return;
+			const currentLabels: string[] = (task.metadata as { labelIds?: string[] })?.labelIds ?? [];
+			if (!currentLabels.includes(tagId)) {
+				tasksStore.updateLabels(taskData.id, [...currentLabels, tagId]);
+			}
+		});
+		return () => tagDropCtx?.clear();
+	});
+
+	// ── DnD: tag dropped onto a task ────────────────────────
+	function handleTagDrop(task: Task, payload: DragPayload) {
+		const tagData = payload.data as TagDragData;
+		const currentLabels: string[] = (task.metadata as { labelIds?: string[] })?.labelIds ?? [];
+		if (!currentLabels.includes(tagData.id)) {
+			tasksStore.updateLabels(task.id, [...currentLabels, tagData.id]);
+		}
+	}
+
+	function tagNotAlreadyOnTask(task: Task) {
+		return (payload: DragPayload) => {
+			const tagData = payload.data as TagDragData;
+			const currentLabels: string[] = (task.metadata as { labelIds?: string[] })?.labelIds ?? [];
+			return !currentLabels.includes(tagData.id);
+		};
+	}
+
 	// View navigation items
 	const views = [
 		{ id: 'inbox', label: 'Inbox', icon: Tray },
@@ -293,6 +343,11 @@
 					role="button"
 					tabindex="0"
 					onclick={() => (selectedTaskId = selectedTaskId === task.id ? null : task.id)}
+					use:dropTarget={{
+						accepts: ['tag'],
+						onDrop: (payload) => handleTagDrop(task, payload),
+						canDrop: tagNotAlreadyOnTask(task),
+					}}
 				>
 					<!-- Completion Toggle -->
 					<button
@@ -337,6 +392,14 @@
 									{task.subtasks.filter((s) => s.isCompleted).length}/{task.subtasks.length} Teilaufgaben
 								</span>
 							{/if}
+							{#each getTaskTags(task).slice(0, 3) as tag (tag.id)}
+								<span
+									class="inline-flex items-center gap-1 rounded-full px-1.5 py-0.5 text-[0.625rem] font-medium"
+									style="background: color-mix(in srgb, {tag.color} 15%, transparent); color: {tag.color}"
+								>
+									{tag.name}
+								</span>
+							{/each}
 						</div>
 
 						<!-- Expanded Detail -->
@@ -469,3 +532,28 @@
 		</div>
 	{/if}
 </div>
+
+<style>
+	/* DnD: tag hovering over task item */
+	:global(.mana-drop-target-hover) {
+		outline: 2px solid var(--color-primary, #6366f1);
+		outline-offset: -2px;
+		border-radius: 0.5rem;
+		background: rgba(99, 102, 241, 0.06) !important;
+	}
+
+	:global(.mana-drop-target-success) {
+		animation: drop-success 400ms ease-out;
+	}
+
+	@keyframes drop-success {
+		0% {
+			outline-color: #10b981;
+			background: rgba(16, 185, 129, 0.1);
+		}
+		100% {
+			outline-color: transparent;
+			background: transparent;
+		}
+	}
+</style>

packages/shared-ui/src/navigation/TagStrip.svelte

@@ -1,6 +1,9 @@
 <script lang="ts">
 	import { goto } from '$app/navigation';
 	import { Tag, Plus, X } from '@manacore/shared-icons';
+	import { dragSource } from '../dnd/drag-source';
+	import { passiveDropZone } from '../dnd/passive-drop';
+	import type { DragPayload } from '../dnd/types';
 
 	interface TagItem {
 		id: string;
@@ -17,6 +20,10 @@
 		onToggle: (tagId: string) => void;
 		/** Called when filter is cleared */
 		onClear: () => void;
+		/** Called when an item (task, card, etc.) is dropped on a tag pill */
+		onTagDrop?: (tagId: string, payload: DragPayload) => void;
+		/** Drag types accepted for drop-on-tag (default: ['task']) */
+		dropAccepts?: string[];
 		/** Link for "Tags verwalten" pill */
 		managementHref?: string;
 		/** Loading state */
@@ -34,6 +41,8 @@
 		selectedIds,
 		onToggle,
 		onClear,
+		onTagDrop,
+		dropAccepts = ['task'],
 		managementHref = '/tags',
 		loading = false,
 		showCreateButton = true,
@@ -93,6 +102,16 @@
 					onclick={() => onToggle(tag.id)}
 					title={tag.name}
 					style="--tag-color: {tag.color || '#8b5cf6'}"
+					use:dragSource={{
+						type: 'tag',
+						data: () => ({ id: tag.id, name: tag.name, color: tag.color || '#8b5cf6' }),
+					}}
+					use:passiveDropZone={{
+						accepts: dropAccepts,
+						onDrop: (payload) => onTagDrop?.(tag.id, payload),
+						highlightClass: 'tag-drop-highlight',
+						disabled: !onTagDrop,
+					}}
 				>
 					<span class="tag-dot"></span>
 					<span class="tag-name">{tag.name}</span>
@@ -343,6 +362,45 @@
 		font-weight: 500;
 	}
 
+	/* DnD: Tag is being dragged */
+	:global(.tag-pill.mana-drag-source-active) {
+		opacity: 0.5;
+		transform: scale(0.95) !important;
+	}
+
+	/* DnD: Item hovering over tag pill */
+	.tag-drop-highlight {
+		transform: scale(1.15) !important;
+		background: var(--tag-color) !important;
+		border-color: var(--tag-color) !important;
+		box-shadow: 0 0 16px color-mix(in srgb, var(--tag-color) 40%, transparent) !important;
+	}
+
+	.tag-drop-highlight .tag-dot {
+		background-color: white !important;
+	}
+
+	.tag-drop-highlight .tag-name {
+		color: white !important;
+	}
+
+	/* DnD: Success flash after drop */
+	:global(.tag-pill.mana-passive-zone-success) {
+		animation: tag-drop-success 400ms ease-out;
+	}
+
+	@keyframes tag-drop-success {
+		0% {
+			transform: scale(1.2);
+		}
+		50% {
+			transform: scale(0.95);
+		}
+		100% {
+			transform: scale(1);
+		}
+	}
+
 	/* Responsive */
 	@media (max-width: 640px) {
 		.tag-strip-wrapper {