Improve admin save UX and portfolio navigation

app/root/portfolio/projects/new/page.tsx

@@ -1,8 +1,8 @@
 import { redirect } from "next/navigation";
 
 import { MotionFade } from "@/components/motion-fade";
+import { FlashMessage } from "@/components/root/flash-message";
 import { PortfolioProjectForm } from "@/components/root/portfolio-project-form";
-import { PortfolioSubnav } from "@/components/root/portfolio-subnav";
 import { RootDashboardShell } from "@/components/root/root-dashboard-shell";
 import { clearAdminSessionCookie, isAdminAuthenticated } from "@/lib/admin-auth";
 import { getMediaOptions } from "@/lib/media";
@@ -58,14 +58,12 @@ export default async function RootNewPortfolioProjectPage({
       logoutAction={logoutAction}
       headerTitle={copy.title}
       headerDescription={copy.subtitle}
-      toolbar={<PortfolioSubnav active="projects" />}
+      saveFormId="portfolio-project-form"
     >
       <div className="space-y-6">
         {searchParams?.error ? (
           <MotionFade delay={0.1}>
-            <p className="rounded-nested border border-destructive/30 bg-destructive/10 px-4 py-3 text-sm text-destructive">
-              {searchParams.error}
-            </p>
+            <FlashMessage type="error" message={searchParams.error} />
           </MotionFade>
         ) : null}
 
@@ -74,6 +72,7 @@ export default async function RootNewPortfolioProjectPage({
             action={saveProjectAction}
             categories={categories}
             mediaOptions={mediaOptions}
+            formId="portfolio-project-form"
             redirectPath="/root/portfolio/projects/new"
             submitLabel="Projekt anlegen"
           />