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/components/meal-plan/pantry-manager.tsx

@@ -3,11 +3,12 @@
 import { useState } from "react";
 import { useRouter } from "next/navigation";
 import { useTranslations } from "next-intl";
-import { Plus, Trash2, AlertTriangle } from "lucide-react";
+import { Plus, Trash2, AlertTriangle, Package } from "lucide-react";
 import { toast } from "sonner";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { PantryScanDialog } from "@/components/pantry/pantry-scan-dialog";
+import { EmptyState } from "@/components/shared/empty-state";
 import {
   AlertDialog,
   AlertDialogAction,
@@ -98,7 +99,7 @@ export function PantryManager({ initialItems }: { initialItems: PantryItem[] })
 
       {/* Item list */}
       {items.length === 0 ? (
-        <p className="text-muted-foreground text-sm">{t("empty")}</p>
+        <EmptyState icon={Package} title={t("empty")} description={t("emptyDescription")} compact />
       ) : (
         <div className="rounded-xl border divide-y">
           {sorted.map((item) => {