ADDED - Admin SEO page, robots/sitemap hardening and media/maintenance security fixes

SEO
- New Settings > SEO admin page (seo_settings in app_config): indexing switch,
  Google/Bing verification, X handle, JSON-LD identity (Person/Organization,
  sameAs), per-locale keywords, readiness checklist and open links for
  sitemap.xml / robots.txt / manifest.
- robots.txt is now dynamic: disallows admin, api, success and coming-soon
  paths; blocks everything while indexing is off or maintenance is on.
- sitemap.xml carries hreflang alternates per URL, lists only categories with
  published projects, and is empty while hidden.
- Metadata: robots + verification meta, og:locale in de_DE/en_US/ar_AR form,
  alternateLocale, twitter site/creator, project cover as OG image with
  article type, noindex on /success and /coming-soon.
- JSON-LD: WebSite + publisher graph on all public pages, CreativeWork per
  project (view-mode independent).

Security
- Maintenance bypass now requires a correctly signed admin cookie; the
  middleware previously only checked the cookie existed. Token helpers moved
  to lib/admin-session-token.ts (shared by proxy.ts and lib/admin-auth.ts).
- Media uploads: magic-byte validation against the declared type, SVG
  sanitization (script/handlers/foreignObject/javascript: rejected), upload
  folder sanitized, kind inferred from the real file.
- Media route: fixed prefix-based path check that accepted sibling
  directories, unknown extensions return 404, nosniff header, CSP sandbox on
  SVG, gif content type added.
- External media URLs: protocol-relative (//host) URLs rejected.

Portfolio
- Project and category slugs share /portfolio/[slug]; saving now rejects a
  slug already used on the other side instead of silently shadowing it.

Tooling/docs
- Lint: ignore scripts/legacy-prisma-seed.cjs, drop unused import.
- New docs/SEO.md; FEATURES, ARCHITECTURE (Drizzle instead of Prisma), admin
  spec and CLAUDE.md updated.
- Tests for all of the above (unit + integration); suite green.

components/admin/admin-dashboard-shell.tsx

@@ -8,6 +8,7 @@ import {
   LogOut,
   Palette,
   PlusSquare,
+  Search,
   ShieldAlert,
   SwatchBook,
   Tags,
@@ -40,6 +41,7 @@ type AdminDashboardCopy = {
   siteSettings: string;
   brandSettings?: string;
   localizationSettings?: string;
+  seoSettings?: string;
   marquee?: string;
   smtp?: string;
   logout: string;
@@ -50,7 +52,7 @@ type AdminDashboardShellProps = {
   copy: AdminDashboardCopy;
   active: "overview" | "maintenance" | "ui-kit" | "portfolio" | "media" | "site-settings" | "smtp" | "marquee";
   portfolioChild?: "overview" | "projects" | "new-project" | "categories";
-  siteSettingsChild?: "brand" | "localization";
+  siteSettingsChild?: "brand" | "localization" | "seo";
   flash?: FlashMessages;
   logoutAction: () => Promise<void>;
   headerTitle: string;
@@ -100,6 +102,8 @@ export async function AdminDashboardShell({
           : active === "site-settings"
             ? siteSettingsChild === "localization"
               ? Languages
+              : siteSettingsChild === "seo"
+                ? Search
               : siteSettingsChild === "brand"
                 ? Palette
                 : Globe2