Prepare frontend for Vercel deployment

frontend/.env.example

@@ -0,0 +1 @@
+VITE_API_URL=https://your-huggingface-space-url.hf.space

frontend/src/App.tsx

@@ -180,8 +180,9 @@ function Dashboard() {
     const formData = new FormData();
     formData.append("file", selectedFile);
 
+    const API_URL = import.meta.env.VITE_API_URL || "";
     try {
-      const response = await fetch("/predict", {
+      const response = await fetch(`${API_URL}/predict`, {
         method: "POST",
         body: formData,
       });

frontend/vercel.json

@@ -0,0 +1,9 @@
+# Vercel Configuration for frontend
+{
+  "version": 2,
+  "framework": "vite",
+  "name": "oil-spill-detection-ui",
+  "installCommand": "npm install",
+  "buildCommand": "npm run build",
+  "outputDirectory": "dist"
+}