Add PayPal donation button to info@nexlab.net

- Add PayPal donation button with blue PayPal branding colors
- Button opens PayPal donation page for info@nexlab.net
- Positioned alongside MetaMask and Bitcoin donation options
- Provides additional donation method for users without crypto wallets
- Maintains consistent styling with other donation buttons

popup.html

@@ -110,6 +110,13 @@
       <div id="web3-status" style="font-size: 9px; color: #666; display: block;">Checking for Web3 wallet...</div>
     </div>
 
+    <div style="margin-bottom: 6px;">
+      <button onclick="window.open('https://www.paypal.com/donate?business=info@nexlab.net', '_blank')" style="background: linear-gradient(45deg, #0070ba, #003087); color: white; border: none; padding: 4px 8px; border-radius: 4px; font-size: 10px; cursor: pointer; margin-bottom: 4px;">
+        💳 Donate with PayPal
+      </button>
+      <div style="font-size: 9px; color: #666;">info@nexlab.net</div>
+    </div>
+    
     <div style="font-size: 10px; margin-bottom: 4px;">
       <strong>ETH/Web3:</strong><br>
       <span style="font-family: monospace; font-size: 9px; word-break: break-all;">0xdA6dAb526515b5cb556d20269207D43fcc760E51</span>