fix: replace emoji flags with SVG dropdown, complete Home's third row

Language switcher was two inline emoji-flag buttons -- emoji flag
rendering is inconsistent across OS/browsers (some render as two-letter
country codes instead of a flag). Replaced with hand-rolled inline SVG
flags (no new dependency for two locales) inside a proper dropdown
menu, trigger showing the current language's flag.

Also added a 9th Home highlight (personalized recommendations, same
copy already written for the Features page) so the lg:grid-cols-3
feature grid's last row has 3 items instead of 2.

v0.48.2

apps/web/app/(marketing)/page.tsx

@@ -7,7 +7,7 @@ import { getEffectiveMarketingLocale } from "@/lib/marketing-locale";
 import { isSignupsDisabled } from "@/lib/site-settings";
 import { buttonVariants } from "@/components/ui/button";
 import { cn } from "@/lib/utils";
-import { Sparkles, Calendar, Package, MessageCircle, Users, ChefHat, Utensils, Wand2 } from "lucide-react";
+import { Sparkles, Calendar, Package, MessageCircle, Users, ChefHat, Utensils, Wand2, Sparkle } from "lucide-react";
 
 const HIGHLIGHTS = [
   { icon: Sparkles, key: "ai" },
@@ -18,6 +18,7 @@ const HIGHLIGHTS = [
   { icon: Wand2, key: "variations" },
   { icon: Users, key: "social" },
   { icon: ChefHat, key: "batchCook" },
+  { icon: Sparkle, key: "recommendations" },
 ] as const;
 
 export default async function MarketingHomePage() {