feat: add internal_component block type with contact form

InternalComponentBlock dispatches on `component` field value.
ContactFormComponent submits via /api/contact (SvelteKit proxy →
CMS /api/forms/kontakt/submit) with honeypot + client_age_ms.
BlockRenderer and block-types.ts updated accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/api/contact/+server.ts

@@ -0,0 +1,32 @@
+import { json } from "@sveltejs/kit";
+import { env } from "$env/dynamic/private";
+import type { RequestHandler } from "./$types";
+
+export const POST: RequestHandler = async ({ request, getClientAddress }) => {
+  const body = await request.json().catch(() => null);
+  if (!body || typeof body !== "object") {
+    return json({ error: "Ungültige Anfrage" }, { status: 400 });
+  }
+
+  const cmsBase = (env.PUBLIC_CMS_URL || "http://localhost:3000").replace(/\/$/, "");
+  const cmsEnv = env.PUBLIC_CMS_ENV || "";
+  const url = cmsEnv
+    ? `${cmsBase}/api/forms/kontakt/submit?_environment=${encodeURIComponent(cmsEnv)}`
+    : `${cmsBase}/api/forms/kontakt/submit`;
+
+  const res = await fetch(url, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      "X-Forwarded-For": getClientAddress(),
+    },
+    body: JSON.stringify(body),
+  });
+
+  if (res.ok) {
+    return json({ ok: true }, { status: 201 });
+  }
+
+  const text = await res.text().catch(() => "");
+  return json({ error: text || "Fehler beim Senden" }, { status: res.status });
+};