feat(frontend): settings page reads user from V2 Identity; drop dead OAuth callback

- dashboard/settings/page.tsx now resolves the current user via getCurrentUser()
  (Identity JWT cookie) instead of the Supabase server client; display name comes
  from Identity's full_name.
- Remove src/app/auth/callback/route.ts — the Supabase OAuth code-exchange
  callback is unreferenced now that auth runs entirely on Identity.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/app/[locale]/dashboard/settings/page.tsx

@@ -4,9 +4,9 @@ import { SettingsBilling } from "@/components/dashboard/settings/SettingsBilling
 import { SettingsNotifications } from "@/components/dashboard/settings/SettingsNotifications";
 import { SettingsProfile } from "@/components/dashboard/settings/SettingsProfile";
 import { SettingsSecurity } from "@/components/dashboard/settings/SettingsSecurity";
+import { getCurrentUser } from "@/lib/auth/session";
 import { createPageMetadata } from "@/lib/metadata";
 import { getUserProfile } from "@/lib/profiles";
-import { createClient } from "@/lib/supabase/server";
 
 export const metadata: Metadata = createPageMetadata({
   title: "Settings",
@@ -17,16 +17,12 @@ export const metadata: Metadata = createPageMetadata({
 export const dynamic = "force-dynamic";
 
 export default async function DashboardSettingsPage() {
-  const supabase = await createClient();
-  const {
-    data: { user },
-  } = await supabase.auth.getUser();
+  // Auth is served by the V2 Identity service (JWT cookie), not Supabase.
+  const user = await getCurrentUser();
 
   const email = user?.email ?? "";
   const displayName =
-    typeof user?.user_metadata?.full_name === "string"
-      ? user.user_metadata.full_name
-      : null;
+    typeof user?.full_name === "string" ? user.full_name : null;
 
   const profile = user ? await getUserProfile(user.id) : null;
   const plan = profile?.plan ?? "free";

src/app/auth/callback/route.ts

@@ -1,21 +0,0 @@
-import { NextResponse } from "next/server";
-
-import { isSupabaseConfigured } from "@/lib/supabase/config";
-import { createClient } from "@/lib/supabase/server";
-
-export async function GET(request: Request) {
-  const { searchParams, origin } = new URL(request.url);
-  const code = searchParams.get("code");
-  const next = searchParams.get("next") ?? "/dashboard";
-
-  if (code && isSupabaseConfigured()) {
-    const supabase = await createClient();
-    const { error } = await supabase.auth.exchangeCodeForSession(code);
-
-    if (!error) {
-      return NextResponse.redirect(`${origin}${next}`);
-    }
-  }
-
-  return NextResponse.redirect(`${origin}/auth?error=auth_callback_failed`);
-}