Add i18n factory + AdminShell My Profile + LogoutButton anchor

- src/i18n/server.ts: createI18nConfig factory consolidating the locale
  resolution chain (cookie → access_token preferred_language claim →
  Accept-Language → default). Reusable across apps; previously each
  frontend reimplemented it.
- AdminShell: thread signoutPath + myProfileUrl (default
  https://my.gosec.internal/profile) into the navbar; render My Profile
  link alongside logout.
- LogoutButton: replace two-step fetch+signOut+redirect with a plain
  anchor pointing at signoutPath — the NextAuth POST-only signout
  endpoint plus form-CSRF flow doesn't need client JS.

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

src/chrome/LogoutButton.tsx

@@ -1,46 +1,45 @@
 "use client";
 
-import { signOut } from "next-auth/react";
-
 /**
- * Default flow (shared org Keycloak):
- *   1. GET /api/auth/logout — host app returns { logoutUrl } pointing at
- *      Keycloak's end_session endpoint (id_token_hint included).
- *   2. next-auth signOut() locally — fires events.signOut for backchannel
- *      revocation; redirect:false so we control the navigation.
- *   3. Navigate to logoutUrl — kills the SSO cookie at Keycloak.
+ * Default flow: a plain anchor to `/api/auth/signout` (overridable via
+ * the `signoutPath` prop). The route handler runs RP-initiated logout
+ * in a single redirect — kills the NextAuth cookie, ends the Keycloak
+ * SSO session, lands on the app's signed-out page.
  *
- * Apps without /api/auth/logout (or that need a different flow) pass
- * `onSignOut` to fully replace this behavior.
+ * Apps with a different shape (no `/api/auth/signout`, need to fire
+ * custom telemetry, etc.) pass `onSignOut` to replace the navigation
+ * with a button + custom handler.
  */
 type LogoutButtonProps = {
   label: string;
+  signoutPath?: string;
   onSignOut?: () => void | Promise<void>;
 };
 
-export function LogoutButton({ label, onSignOut }: LogoutButtonProps) {
-  const handleLogout = async () => {
-    if (onSignOut) {
-      await onSignOut();
-      return;
-    }
-
-    let logoutUrl = "/logged-out";
-    try {
-      const res = await fetch("/api/auth/logout");
-      const body = await res.json();
-      if (body?.logoutUrl) logoutUrl = body.logoutUrl;
-    } catch {
-      // fall through with local-only logout
-    }
-    await signOut({ redirect: false });
-    window.location.href = logoutUrl;
-  };
+export function LogoutButton({
+  label,
+  signoutPath = "/api/auth/signout",
+  onSignOut,
+}: LogoutButtonProps) {
+  if (onSignOut) {
+    return (
+      <button
+        type="button"
+        onClick={() => {
+          void onSignOut();
+        }}
+        className="dropdown-item"
+      >
+        <i className="ph-sign-out me-2"></i>
+        {label}
+      </button>
+    );
+  }
 
   return (
-    <button type="button" onClick={handleLogout} className="dropdown-item">
+    <a href={signoutPath} className="dropdown-item">
       <i className="ph-sign-out me-2"></i>
       {label}
-    </button>
+    </a>
   );
 }