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.

tests/unit/seo-report.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, it } from "vitest";
+
+import { buildSeoChecklist, summarizeSeoChecklist } from "@/lib/seo-report";
+import { buildDefaultSeoSettings } from "@/lib/seo-settings";
+import { buildDefaultSiteSettings, getDefaultSiteSettingsMediaBindings } from "@/lib/site-settings";
+
+function run(overrides: Partial<Parameters<typeof buildSeoChecklist>[0]> = {}) {
+  return buildSeoChecklist({
+    seo: buildDefaultSeoSettings(),
+    settings: buildDefaultSiteSettings(),
+    bindings: getDefaultSiteSettingsMediaBindings(),
+    maintenanceEnabled: false,
+    publishedProjectCount: 2,
+    sitemapEntryCount: 12,
+    siteUrl: "https://mohfarawati.de",
+    ...overrides,
+  });
+}
+
+describe("buildSeoChecklist", () => {
+  it("flags maintenance mode as an indexing error", () => {
+    const check = run({ maintenanceEnabled: true }).find((entry) => entry.id === "indexing");
+    expect(check?.status).toBe("error");
+    expect(check?.detail).toMatch(/Wartungsmodus/);
+  });
+
+  it("flags disabled indexing and passes when enabled", () => {
+    const seo = { ...buildDefaultSeoSettings(), allowIndexing: false };
+    expect(run({ seo }).find((entry) => entry.id === "indexing")?.status).toBe("error");
+    expect(run().find((entry) => entry.id === "indexing")?.status).toBe("ok");
+  });
+
+  it("warns about localhost as public url", () => {
+    expect(run({ siteUrl: "http://localhost:3014" }).find((entry) => entry.id === "site-url")?.status).toBe("warn");
+  });
+
+  it("grades description length per locale", () => {
+    const settings = buildDefaultSiteSettings();
+    settings.locales.de.siteDescription = "";
+    settings.locales.en.siteDescription = "x".repeat(80);
+    const checks = run({ settings });
+    expect(checks.find((entry) => entry.id === "description-de")?.status).toBe("error");
+    expect(checks.find((entry) => entry.id === "description-en")?.status).toBe("ok");
+    expect(checks.find((entry) => entry.id === "description-ar")?.status).toBe("warn");
+  });
+
+  it("summarizes counts", () => {
+    const summary = summarizeSeoChecklist(run());
+    expect(summary.ok + summary.warn + summary.error).toBe(run().length);
+  });
+});