feat: add changelog and versioning, surface it in admin

Bumps version to 0.2.0 (root + apps/web package.json) and adds
CHANGELOG.md as the canonical human-readable history, mirrored by
apps/web/lib/changelog.ts as the in-app data source (single
ChangelogList component renders both).

- /changelog: user-facing page, linked from the account dropdown.
- /admin/changelog: same list, plus a "Version" card on the admin
  overview dashboard linking to it.

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

apps/web/app/admin/page.tsx

@@ -1,9 +1,11 @@
 import type { Metadata } from "next";
+import Link from "next/link";
 import { db } from "@epicure/db";
 import { users, recipes, userUsage, recipePhotos } from "@epicure/db";
 import { count, eq, sql } from "@epicure/db";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
-import { Users, BookOpen, Sparkles, Image } from "lucide-react";
+import { Users, BookOpen, Sparkles, Image, History } from "lucide-react";
+import { APP_VERSION, CHANGELOG } from "@/lib/changelog";
 
 export const metadata: Metadata = {};
 
@@ -46,6 +48,22 @@ export default async function AdminPage() {
           </Card>
         ))}
       </div>
+
+      <Card>
+        <CardHeader className="flex flex-row items-center justify-between pb-2">
+          <CardTitle className="text-sm font-medium text-muted-foreground">Version</CardTitle>
+          <History className="h-4 w-4 text-muted-foreground" />
+        </CardHeader>
+        <CardContent>
+          <div className="text-2xl font-bold">v{APP_VERSION}</div>
+          <p className="text-xs text-muted-foreground mt-1">
+            Released {CHANGELOG[0]?.date} ·{" "}
+            <Link href="/admin/changelog" className="underline hover:text-foreground">
+              View changelog
+            </Link>
+          </p>
+        </CardContent>
+      </Card>
     </div>
   );
 }