feat: add real-time collaborative shopping list at /cospend/list

Real-time shopping list with SSE sync between multiple clients, automatic
item categorization using embedding-based classification + Bring icon
matching, and card-based UI with category grouping.

- SSE broadcast for live sync (add/check/remove items across tabs)
- Hybrid categorizer: direct catalog lookup → category-scoped embedding
  search → per-category default icons, with DB caching
- 388 Bring catalog icons matched via multilingual-e5-base embeddings
- 170+ English→German icon aliases for reliable cross-language matching
- Move cospend dashboard to /cospend/dash, /cospend redirects to list
- Shopping icon on homepage links to /cospend/list

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.6.1",
+	"version": "1.7.0",
 	"private": true,
 	"type": "module",
 	"scripts": {