feat(library): register as workbench app (Kreativ category)

Library was listed in MANA_APPS (for the tier/branding registry) and had
a /library route, but it wasn't yet registered in the workbench app
registry — so users couldn't add it as a tile to their Workbench scene.

Adds:
  - registerApp({ id: 'library', icon: Stack, … }) in app-registry/apps.ts
    with a "+ Neuer Eintrag" context-menu action (emits the standard
    mana:quick-action CustomEvent, ready to be listened to in ListView
    once we want an in-workbench create flow).
  - library → 'creative' entry in app-registry/categories.ts so it
    appears in the Kreativ section of the app picker.

Only the list view is registered; the detail view still uses the
route-based pattern (/library/entry/[id]) and the route-level +page.svelte
wrapper. Migrating DetailView to the workbench ViewProps shape (params +
navigate + goBack) is deferred — the route works fine for now.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/mana/apps/web/src/lib/app-registry/apps.ts

@@ -73,6 +73,7 @@ import {
 	Crown,
 	ShootingStar,
 	CloudSun,
+	Stack,
 } from '@mana/shared-icons';
 
 // ── Apps with entity capabilities ───────────────────────────
@@ -1239,3 +1240,27 @@ registerApp({
 		list: { load: () => import('$lib/modules/feedback/ListView.svelte') },
 	},
 });
+
+registerApp({
+	id: 'library',
+	name: 'Bibliothek',
+	color: '#a855f7',
+	icon: Stack,
+	views: {
+		// Detail view uses the route-based pattern (/library/entry/[id]); the
+		// workbench detail-slot (ViewProps params/navigate) pattern is not
+		// wired up yet. Clicks on a card in the list view navigate via goto().
+		list: { load: () => import('$lib/modules/library/ListView.svelte') },
+	},
+	contextMenuActions: [
+		{
+			id: 'new-entry',
+			label: 'Neuer Eintrag',
+			icon: Plus,
+			action: () =>
+				window.dispatchEvent(
+					new CustomEvent('mana:quick-action', { detail: { app: 'library', action: 'new' } })
+				),
+		},
+	],
+});

apps/mana/apps/web/src/lib/app-registry/categories.ts

@@ -107,6 +107,7 @@ export const APP_CATEGORY_MAP: Record<string, AppCategory> = {
 	guides: 'creative',
 	quotes: 'creative',
 	uload: 'creative',
+	library: 'creative',
 	playground: 'creative',
 
 	// System — settings, admin, meta