fix: use grey well for contract address display in address-token view

- Replace border-b styling with bg-hover + dashed border for visual
  distinction from wallet address
- Rename label from "Token Contract" to "Contract Address"
- Addresses feedback on #9

src/popup/index.html

@@ -361,7 +361,7 @@
                 <!-- token contract details (ERC-20 only) -->
                 <div
                     id="address-token-contract-info"
-                    class="border-b border-border-light pb-2 mb-2 text-xs hidden"
+                    class="bg-hover border border-border border-dashed p-3 mb-3 text-xs hidden"
                 ></div>
 
                 <!-- actions -->