feat: modernize admin panel UI and add openinary integration

lib/openinary-url.ts

@@ -0,0 +1,5 @@
+const BASE = process.env.NEXT_PUBLIC_OPENINARY_URL;
+
+export function optimizedImage(path: string, params: string) {
+  return `${BASE}/t/${params}/${path}`;
+}

lib/openinary.ts

@@ -0,0 +1,19 @@
+export async function uploadToOpeninary(file: File, folder: string) {
+  const formData = new FormData();
+  formData.append("files", file);
+  formData.append("folder", folder);
+
+  const res = await fetch(`${process.env.OPENINARY_API_URL}/api/upload`, {
+    method: "POST",
+    headers: { Authorization: `Bearer ${process.env.OPENINARY_API_KEY}` },
+    body: formData,
+  });
+
+  if (!res.ok) {
+    const errorText = await res.text();
+    console.error("Openinary upload error:", errorText);
+    throw new Error("Upload başarısız: " + errorText);
+  }
+  const data = await res.json();
+  return data.files[0]; // { path, url, size, ... }
+}