refactor(mana/web): extract addTagId / removeTagIdWithUndo helpers

Four ListViews (calendar, contacts, places, todo) reimplemented the
same drag-drop tag append logic, and four matching DetailViews
reimplemented the same "remove tag with undo toast" logic. Extract
both into pure helpers in $lib/data/tag-mutations.ts that take a
store-agnostic update function — works for the standard tagIds
modules and for todo's metadata.labelIds via tasksStore.updateLabels.

Side win: places/views/DetailView's removeTag had no undo toast
(every other module did). Consolidating fixes the inconsistency.

zitare is the outlier — its drag target is a Quote, but the tags
live on a (possibly-not-yet-existing) Favorite record. Stays custom.

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

apps/mana/apps/web/src/lib/data/tag-mutations.ts

@@ -0,0 +1,67 @@
+/**
+ * Tag mutation helpers — shared add/remove logic for entity.tagIds fields.
+ *
+ * Every module that supports tagging on its records (calendar events,
+ * contacts, places, todo tasks, …) reimplemented the same two operations:
+ *
+ *   - "append a tag if not already present" (drag-drop from tag strip)
+ *   - "remove a tag, with undo toast" (click on a tag pill in the detail view)
+ *
+ * These helpers stay store-agnostic — the caller passes the current
+ * `tagIds` array and an `update` function that knows which store/field to
+ * write to. That keeps them usable for tasks (which write `metadata.labelIds`
+ * via `tasksStore.updateLabels`) as well as the standard `tagIds` modules.
+ */
+
+import { toastStore } from '@mana/shared-ui/toast';
+
+type UpdateFn = (next: string[]) => Promise<void> | void;
+
+/**
+ * Append `tagId` to `current` and call `update` with the result.
+ * No-op if the tag is already present.
+ *
+ * @example
+ * ```svelte
+ * use:dropTarget={{
+ *   accepts: ['tag'],
+ *   onDrop: (p) => addTagId(
+ *     contact.tagIds ?? [],
+ *     (p.data as TagDragData).id,
+ *     (next) => contactsStore.updateTagIds(contact.id, next),
+ *   ),
+ * }}
+ * ```
+ */
+export async function addTagId(current: string[], tagId: string, update: UpdateFn): Promise<void> {
+	if (current.includes(tagId)) return;
+	await update([...current, tagId]);
+}
+
+/**
+ * Remove `tagId` from `current`, call `update` with the filtered list,
+ * and show a toast with an undo action that reinstates the original list.
+ *
+ * @example
+ * ```ts
+ * async function removeTag(tagId: string) {
+ *   await removeTagIdWithUndo(
+ *     contact.tagIds ?? [],
+ *     tagId,
+ *     (next) => contactsStore.updateTagIds(contactId, next),
+ *   );
+ * }
+ * ```
+ */
+export async function removeTagIdWithUndo(
+	current: string[],
+	tagId: string,
+	update: UpdateFn,
+	undoLabel = 'Tag entfernt'
+): Promise<void> {
+	const removed = current.filter((id) => id !== tagId);
+	await update(removed);
+	toastStore.undo(undoLabel, () => {
+		void update(current);
+	});
+}

apps/mana/apps/web/src/lib/modules/calendar/ListView.svelte

@@ -14,6 +14,7 @@
 	import { dropTarget, dragSource } from '@mana/shared-ui/dnd';
 	import type { TagDragData } from '@mana/shared-ui/dnd';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
+	import { addTagId } from '$lib/data/tag-mutations';
 
 	let { navigate, goBack, params }: ViewProps = $props();
 
@@ -23,10 +24,9 @@
 	function handleTagDrop(eventId: string, tagData: TagDragData) {
 		const event = allItems.find((e) => e.id === eventId);
 		if (!event) return;
-		const current = event.tagIds ?? [];
-		if (!current.includes(tagData.id)) {
-			eventsStore.updateTagIds(eventId, [...current, tagData.id]);
-		}
+		void addTagId(event.tagIds ?? [], tagData.id, (next) =>
+			eventsStore.updateTagIds(eventId, next)
+		);
 	}
 
 	const itemsQuery = useAllCalendarItems();

apps/mana/apps/web/src/lib/modules/calendar/views/DetailView.svelte

@@ -15,6 +15,7 @@
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
 	import LinkedItems from '$lib/components/links/LinkedItems.svelte';
 	import { toastStore } from '@mana/shared-ui/toast';
+	import { removeTagIdWithUndo } from '$lib/data/tag-mutations';
 
 	let { navigate, params, goBack }: ViewProps = $props();
 	let eventId = $derived(params.eventId as string);
@@ -68,12 +69,9 @@
 	let eventTags = $derived(getTagsByIds(allTags, detail.entity?.tagIds ?? []));
 
 	async function removeTag(tagId: string) {
-		const current = detail.entity?.tagIds ?? [];
-		const removed = current.filter((id) => id !== tagId);
-		await eventsStore.updateTagIds(eventId, removed);
-		toastStore.undo('Tag entfernt', () => {
-			eventsStore.updateTagIds(eventId, current);
-		});
+		await removeTagIdWithUndo(detail.entity?.tagIds ?? [], tagId, (next) =>
+			eventsStore.updateTagIds(eventId, next)
+		);
 	}
 
 	async function saveField() {

apps/mana/apps/web/src/lib/modules/contacts/ListView.svelte

@@ -14,6 +14,7 @@
 	import { dropTarget, dragSource } from '@mana/shared-ui/dnd';
 	import type { TagDragData } from '@mana/shared-ui/dnd';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
+	import { addTagId } from '$lib/data/tag-mutations';
 
 	let { navigate, goBack, params }: ViewProps = $props();
 
@@ -23,10 +24,9 @@
 	function handleTagDrop(contactId: string, tagData: TagDragData) {
 		const contact = contacts.find((c) => c.id === contactId);
 		if (!contact) return;
-		const current = contact.tagIds ?? [];
-		if (!current.includes(tagData.id)) {
-			contactsStore.updateTagIds(contactId, [...current, tagData.id]);
-		}
+		void addTagId(contact.tagIds ?? [], tagData.id, (next) =>
+			contactsStore.updateTagIds(contactId, next)
+		);
 	}
 
 	let contacts$ = useLiveQueryWithDefault(async () => {

apps/mana/apps/web/src/lib/modules/contacts/views/DetailView.svelte

@@ -11,7 +11,7 @@
 	import type { LocalContact } from '../types';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
 	import LinkedItems from '$lib/components/links/LinkedItems.svelte';
-	import { toastStore } from '@mana/shared-ui/toast';
+	import { removeTagIdWithUndo } from '$lib/data/tag-mutations';
 
 	let { navigate, params, goBack }: ViewProps = $props();
 	let contactId = $derived(params.contactId as string);
@@ -58,12 +58,9 @@
 	let contactTags = $derived(getTagsByIds(allTags, detail.entity?.tagIds ?? []));
 
 	async function removeTag(tagId: string) {
-		const current = detail.entity?.tagIds ?? [];
-		const removed = current.filter((id) => id !== tagId);
-		await contactsStore.updateTagIds(contactId, removed);
-		toastStore.undo('Tag entfernt', () => {
-			contactsStore.updateTagIds(contactId, current);
-		});
+		await removeTagIdWithUndo(detail.entity?.tagIds ?? [], tagId, (next) =>
+			contactsStore.updateTagIds(contactId, next)
+		);
 	}
 
 	function initials(c: LocalContact): string {

apps/mana/apps/web/src/lib/modules/places/ListView.svelte

@@ -14,6 +14,7 @@
 	import { dropTarget, dragSource } from '@mana/shared-ui/dnd';
 	import type { TagDragData } from '@mana/shared-ui/dnd';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
+	import { addTagId } from '$lib/data/tag-mutations';
 
 	let { navigate, goBack, params }: ViewProps = $props();
 
@@ -23,10 +24,9 @@
 	function handleTagDrop(placeId: string, tagData: TagDragData) {
 		const place = places.find((p) => p.id === placeId);
 		if (!place) return;
-		const current = place.tagIds ?? [];
-		if (!current.includes(tagData.id)) {
-			placesStore.updateTagIds(placeId, [...current, tagData.id]);
-		}
+		void addTagId(place.tagIds ?? [], tagData.id, (next) =>
+			placesStore.updateTagIds(placeId, next)
+		);
 	}
 
 	let places = $state<LocalPlace[]>([]);

apps/mana/apps/web/src/lib/modules/places/views/DetailView.svelte

@@ -13,6 +13,7 @@
 	import type { LocalPlace, PlaceCategory, LocalLocationLog } from '../types';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
 	import LinkedItems from '$lib/components/links/LinkedItems.svelte';
+	import { removeTagIdWithUndo } from '$lib/data/tag-mutations';
 
 	let { navigate, params, goBack }: ViewProps = $props();
 	let placeId = $derived(params.placeId as string);
@@ -64,10 +65,8 @@
 	];
 
 	async function removeTag(tagId: string) {
-		const current = detail.entity?.tagIds ?? [];
-		await placesStore.updateTagIds(
-			placeId,
-			current.filter((id) => id !== tagId)
+		await removeTagIdWithUndo(detail.entity?.tagIds ?? [], tagId, (next) =>
+			placesStore.updateTagIds(placeId, next)
 		);
 	}
 

apps/mana/apps/web/src/lib/modules/todo/ListView.svelte

@@ -20,6 +20,7 @@
 	import { dropTarget, dragSource } from '@mana/shared-ui/dnd';
 	import type { TagDragData } from '@mana/shared-ui/dnd';
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
+	import { addTagId } from '$lib/data/tag-mutations';
 	import VoiceCaptureBar from '$lib/components/voice/VoiceCaptureBar.svelte';
 
 	let { navigate, goBack, params }: ViewProps = $props();
@@ -34,10 +35,7 @@
 	function handleTagDrop(taskId: string, tagData: TagDragData) {
 		const task = tasks.find((t) => t.id === taskId);
 		if (!task) return;
-		const current = getTaskTagIds(task);
-		if (!current.includes(tagData.id)) {
-			tasksStore.updateLabels(taskId, [...current, tagData.id]);
-		}
+		void addTagId(getTaskTagIds(task), tagData.id, (next) => tasksStore.updateLabels(taskId, next));
 	}
 
 	type ViewFilter = 'inbox' | 'today' | 'overdue';

apps/mana/apps/web/src/lib/modules/todo/views/DetailView.svelte

@@ -17,6 +17,7 @@
 	import { useAllTags, getTagsByIds } from '@mana/shared-stores';
 	import LinkedItems from '$lib/components/links/LinkedItems.svelte';
 	import { toastStore } from '@mana/shared-ui/toast';
+	import { removeTagIdWithUndo } from '$lib/data/tag-mutations';
 
 	let { navigate, params, goBack }: ViewProps = $props();
 	let taskId = $derived(params.taskId as string);
@@ -73,12 +74,9 @@
 	let taskTags = $derived(getTagsByIds(allTags, getTaskTagIds()));
 
 	async function removeTag(tagId: string) {
-		const current = getTaskTagIds();
-		const removed = current.filter((id) => id !== tagId);
-		await tasksStore.updateLabels(taskId, removed);
-		toastStore.undo('Tag entfernt', () => {
-			tasksStore.updateLabels(taskId, current);
-		});
+		await removeTagIdWithUndo(getTaskTagIds(), tagId, (next) =>
+			tasksStore.updateLabels(taskId, next)
+		);
 	}
 
 	async function saveField() {