feat: shared, more pleasing empty-state component across the app

Every "nothing here" page had its own copy-pasted dashed-border box —
icon + one muted line, inconsistent (some had a CTA, some didn't, no
description text anywhere). Replaced with one shared EmptyState
component: icon in a soft tinted circle, a real heading plus optional
description, and primary/secondary actions (either a Link or an
arbitrary action slot for things like "New Collection" that open a
dialog rather than navigate).

Applied to: recipes (no recipes / no search match), favorites, feed
(no one followed / no new posts / trending / for-you), collections
(index + detail), shopping lists, pantry, notifications, can-cook.
Left the small inline "no trending"/"no recent" lines inside Explore's
already-labeled sections and the notification-bell dropdown alone —
different context, a full empty-state box would be heavier than the
space warrants.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/messages/en.json

@@ -571,7 +571,10 @@
     "tabFavorites": "Favorites",
     "favoritesCount": "{count} favorited recipe",
     "favoritesCountPlural": "{count} favorited recipes",
-    "favoritesEmpty": "No favorited recipes yet — tap the heart on any recipe to save it here."
+    "favoritesEmpty": "No favorited recipes yet — tap the heart on any recipe to save it here.",
+    "favoritesEmptyTitle": "No favorites yet",
+    "exploreRecipes": "Explore recipes",
+    "emptyStateDescription": "Create your own, import from a URL, or let AI generate one to get started."
   },
   "recipeNotes": {
     "title": "Your private notes",
@@ -742,6 +745,7 @@
     "removeConfirmTitle": "Remove item?",
     "removeConfirmDescription": "Remove \"{name}\" from your pantry?",
     "empty": "No pantry items yet.",
+    "emptyDescription": "Add items by hand, or scan a barcode / photo to fill it in fast.",
     "expired": "Expired",
     "expiresInDays": "Expires in {days}d",
     "expiresOn": "Expires {date}",
@@ -775,6 +779,8 @@
   "feed": {
     "title": "Feed",
     "followEmpty": "Follow chefs to see their recipes here.",
+    "followEmptyDescription": "Your following feed fills up as soon as you follow a few people.",
+    "findPeople": "Find people to follow",
     "noNew": "No new recipes from people you follow.",
     "following": "Following",
     "trending": "Trending",
@@ -790,6 +796,7 @@
     "title": "Shopping Lists",
     "subtitle": "Plan your grocery runs",
     "empty": "No shopping lists yet",
+    "emptyDescription": "Generate one from a meal plan, or start one from scratch.",
     "listEmpty": "Empty",
     "generated": "Generated",
     "shareTitle": "Share shopping list",
@@ -850,6 +857,8 @@
     "title": "Collections",
     "subtitle": "Curate your favorite recipes into collections",
     "empty": "No collections yet",
+    "emptyDescription": "Group your recipes by theme, occasion, or however makes sense to you.",
+    "emptyCollection": "No recipes in this collection yet.",
     "public": "Public",
     "recipeCount": "{count} recipe",
     "recipeCountPlural": "{count} recipes",