feat(web): language switcher in dashboard header + shared component

Extract the footer's TR/EN toggle into a reusable LanguageSwitcher with
two variants: `inline` (segmented row, used by the footer) and
`dropdown` (round Globe icon + menu with active check). Add the dropdown
variant to the dashboard header next to the theme toggle so app users
can switch language without the marketing footer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/components/language-switcher.tsx

@@ -0,0 +1,67 @@
+import { type Locale, useTranslation } from "@/lib/i18n";
+import { DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuTrigger } from "@sase/ui";
+import { Check, Globe } from "lucide-react";
+
+const LOCALES: { code: Locale; label: string; name: string }[] = [
+  { code: "tr", label: "TR", name: "Türkçe" },
+  { code: "en", label: "EN", name: "English" },
+];
+
+/**
+ * Language switcher wired to the i18n store.
+ * - `inline`: segmented TR/EN row (footer)
+ * - `dropdown`: round Globe icon button + menu (app header)
+ */
+export function LanguageSwitcher({ variant = "inline" }: { variant?: "inline" | "dropdown" }) {
+  const { t, locale, setLocale } = useTranslation();
+
+  if (variant === "dropdown") {
+    return (
+      <DropdownMenu>
+        <DropdownMenuTrigger asChild>
+          <button
+            type="button"
+            aria-label={t("footer.language")}
+            className="flex size-9 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-accent hover:text-foreground"
+          >
+            <Globe className="size-4" />
+          </button>
+        </DropdownMenuTrigger>
+        <DropdownMenuContent align="end" className="w-40">
+          {LOCALES.map(({ code, name }) => (
+            <DropdownMenuItem
+              key={code}
+              onSelect={() => setLocale(code)}
+              className="justify-between"
+            >
+              {name}
+              {locale === code && <Check className="size-4 text-brand" />}
+            </DropdownMenuItem>
+          ))}
+        </DropdownMenuContent>
+      </DropdownMenu>
+    );
+  }
+
+  return (
+    // biome-ignore lint/a11y/useSemanticElements: a button group, not a form fieldset; role="group" is the correct ARIA here
+    <div className="flex items-center gap-1 text-sm" role="group" aria-label={t("footer.language")}>
+      <Globe className="mr-1 size-4 text-muted-foreground" aria-hidden="true" />
+      {LOCALES.map(({ code, label }) => (
+        <button
+          key={code}
+          type="button"
+          onClick={() => setLocale(code)}
+          aria-pressed={locale === code}
+          className={`rounded-md px-2 py-1 transition-colors ${
+            locale === code
+              ? "font-semibold text-foreground"
+              : "text-muted-foreground hover:text-foreground"
+          }`}
+        >
+          {label}
+        </button>
+      ))}
+    </div>
+  );
+}

apps/web/src/components/site-footer.tsx

@@ -1,12 +1,8 @@
-import { type Locale, useTranslation } from "@/lib/i18n";
+import { LanguageSwitcher } from "@/components/language-switcher";
+import { useTranslation } from "@/lib/i18n";
 import { Separator } from "@sase/ui";
 import { Link } from "@tanstack/react-router";
-import { Facebook, Globe, Instagram, Linkedin } from "lucide-react";
+import { Facebook, Instagram, Linkedin } from "lucide-react";
-
-const LOCALES: { code: Locale; label: string }[] = [
-  { code: "tr", label: "TR" },
-  { code: "en", label: "EN" },
-];
 
 const SOCIALS: {
   label: string;
@@ -23,29 +19,7 @@ const SOCIALS: {
 ];
 
 export function SiteFooter({ variant = "full" }: { variant?: "full" | "compact" }) {
-  const { t, locale, setLocale } = useTranslation();
+  const { t } = useTranslation();
-
-  const languageSwitcher = (
-    // biome-ignore lint/a11y/useSemanticElements: a button group, not a form fieldset; role="group" is the correct ARIA here
-    <div className="flex items-center gap-1 text-sm" role="group" aria-label={t("footer.language")}>
-      <Globe className="mr-1 size-4 text-muted-foreground" aria-hidden="true" />
-      {LOCALES.map(({ code, label }) => (
-        <button
-          key={code}
-          type="button"
-          onClick={() => setLocale(code)}
-          aria-pressed={locale === code}
-          className={`rounded-md px-2 py-1 transition-colors ${
-            locale === code
-              ? "font-semibold text-foreground"
-              : "text-muted-foreground hover:text-foreground"
-          }`}
-        >
-          {label}
-        </button>
-      ))}
-    </div>
-  );
 
   // Compact variant — single line for app/dashboard layouts.
   if (variant === "compact") {
@@ -183,7 +157,7 @@ export function SiteFooter({ variant = "full" }: { variant?: "full" | "compact"
           <p className="text-sm text-muted-foreground">
             &copy; {new Date().getFullYear()} Sase.tr. {t("footer.rights")}
           </p>
-          {languageSwitcher}
+          <LanguageSwitcher variant="inline" />
         </div>
       </div>
     </footer>

apps/web/src/routes/dashboard.tsx

@@ -1,3 +1,4 @@
+import { LanguageSwitcher } from "@/components/language-switcher";
 import { SiteFooter } from "@/components/site-footer";
 import { TrialUrgencyBanner } from "@/components/trial-urgency-banner";
 import { useAuth } from "@/hooks/use-auth";
@@ -493,6 +494,7 @@ function DashboardLayout() {
                   </Button>
                 </Link>
               )}
+              <LanguageSwitcher variant="dropdown" />
               <button
                 type="button"
                 onClick={toggleTheme}