Enable KeyStatic CMS for production

Changes:
- Added Netlify adapter for server-side rendering
- Changed output mode from static to server
- Updated KeyStatic storage from local to GitHub
- Removed SKIP_KEYSTATIC from Netlify build
- KeyStatic Admin UI will be available at /keystatic

Features:
- Server-side rendering with Netlify Functions
- GitHub integration for content management
- Production-ready KeyStatic Admin UI

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

.netlify/build/pages/api/dmr-contacts.json.astro.mjs

@@ -0,0 +1,21 @@
+export { renderers } from '../../renderers.mjs';
+
+async function GET() {
+  const contacts = [
+    { id: "2867241", callsign: "YM0KTC", name: "ARC Merkez", location: "Bölge 0 - İstanbul", type: "repeater" },
+    { id: "2866808", callsign: "YM1KTC", name: "İstanbul Röle", location: "Bölge 1 - İstanbul", type: "repeater" },
+    { id: "2867887", callsign: "YM2KTR", name: "Ankara Röle", location: "Bölge 2 - Ankara", type: "repeater" },
+    { id: "2867234", callsign: "YM3KTC", name: "İzmir Röle", location: "Bölge 3 - İzmir", type: "repeater" },
+    { id: "2867235", callsign: "YM4KTC", name: "Antalya Röle", location: "Bölge 4 - Antalya", type: "repeater" }
+  ];
+  return Response.json(contacts);
+}
+
+const _page = /*#__PURE__*/Object.freeze(/*#__PURE__*/Object.defineProperty({
+  __proto__: null,
+  GET
+}, Symbol.toStringTag, { value: 'Module' }));
+
+const page = () => _page;
+
+export { page };