feat(inbox): add expandable details to digest notes

Digest notes only showed counts. Now a digest note opens to list its
games and items, grouped by kind. The list loads once, from
GET /api/inbox/{id}/details. Achievements show 5 per game first.

public/i18n/en.json

@@ -969,7 +969,14 @@
     "PART_STATUS_CHANGES_one": "{{count}} status change",
     "PART_STATUS_CHANGES_other": "{{count}} status changes",
     "PART_WISHLIST_ADDS_one": "{{count}} new wishlist item",
-    "PART_WISHLIST_ADDS_other": "{{count}} new wishlist items"
+    "PART_WISHLIST_ADDS_other": "{{count}} new wishlist items",
+    "DETAIL_NEW_GAME": "New games",
+    "DETAIL_ACHIEVEMENT": "Achievements and trophies",
+    "DETAIL_STATUS": "Status changes",
+    "DETAIL_WISHLIST": "Wishlist",
+    "SHOW_ALL": "Show all {{count}}",
+    "DETAILS_GONE": "No details any more: you no longer follow this person or the part is private now.",
+    "DETAILS_ERROR": "The details could not be loaded."
   },
   "NEWS": {
     "TITLE": "What's new",