feat: admin Ingredients CRUD UI; fix "page not found" after deleting shopping list/recipe/collection (v0.85.0)

Admin > Ingredients lets admins add/edit/delete canonical ingredients and their aliases (e.g. "sel"/"sel fin"/"table salt") without touching code — previously only settable by hand in packages/db/src/seed.ts. Deleting just unlinks referencing pantry items/recipe ingredients (onDelete: set null), nothing else changes.

Fixed: deleting a shopping list, recipe, or collection from its own detail page used router.push to navigate away, leaving the deleted resource's URL in browser history — one back-button press landed on a real "Page not found" screen. All three now use router.replace so the dead URL never sits in history.

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

apps/web/app/admin/ingredients/page.tsx

@@ -0,0 +1,31 @@
+import type { Metadata } from "next";
+import { db, ingredients, asc } from "@epicure/db";
+import { requireFullAdminPage } from "@/lib/require-admin-page";
+import { IngredientsManager } from "@/components/admin/ingredients-manager";
+
+export const metadata: Metadata = {};
+
+export default async function AdminIngredientsPage() {
+  await requireFullAdminPage();
+
+  const rows = await db.select().from(ingredients).orderBy(asc(ingredients.name));
+
+  return (
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-2xl font-bold tracking-tight">Ingredients</h1>
+        <p className="text-muted-foreground text-sm mt-1">
+          Canonical ingredients and their name variants (e.g. &quot;sel&quot;, &quot;sel fin&quot;, &quot;table salt&quot;) — lets pantry items and recipe ingredients written differently still be recognized as the same thing. Used by pantry add/edit, can-cook scoring, auto-deduct on cook, and shopping-list pantry-awareness.
+        </p>
+      </div>
+      <IngredientsManager
+        initialIngredients={rows.map((r) => ({
+          id: r.id,
+          name: r.name,
+          aliases: r.aliases,
+          category: r.category,
+        }))}
+      />
+    </div>
+  );
+}