feat: add contract address display to AddressToken view

Show the ERC-20 contract address in a grey well below the token balance.
Full address displayed with click-to-copy and Etherscan link.

Also fix pre-existing prettier formatting in transactions.js.

Closes #9

src/popup/index.html

@@ -358,6 +358,23 @@
                     </div>
                 </div>
 
+                <!-- contract address well -->
+                <div
+                    id="address-token-contract-well"
+                    class="hidden bg-gray-200 p-2 mb-3 text-xs"
+                >
+                    <div class="text-muted mb-1">Contract Address</div>
+                    <div class="flex items-center">
+                        <span id="address-token-contract-dot"></span>
+                        <span
+                            id="address-token-contract-full"
+                            class="break-all underline decoration-dashed cursor-pointer"
+                            title="Click to copy"
+                        ></span>
+                        <span id="address-token-contract-etherscan-link"></span>
+                    </div>
+                </div>
+
                 <!-- actions -->
                 <div class="flex gap-2 mb-3">
                     <button

src/popup/views/addressToken.js

@@ -130,6 +130,21 @@ function show() {
     // Single token balance line (no tokenId — not clickable here)
     $("address-token-balance").innerHTML = balanceLine(symbol, amount, price);
 
+    // Contract address well (ERC-20 tokens only)
+    const contractWell = $("address-token-contract-well");
+    if (tokenId !== "ETH") {
+        contractWell.classList.remove("hidden");
+        $("address-token-contract-dot").innerHTML = addressDotHtml(tokenId);
+        const contractEl = $("address-token-contract-full");
+        contractEl.textContent = tokenId;
+        contractEl.dataset.full = tokenId;
+        const contractLink = `https://etherscan.io/token/${tokenId}`;
+        $("address-token-contract-etherscan-link").innerHTML =
+            `<a href="${contractLink}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+    } else {
+        contractWell.classList.add("hidden");
+    }
+
     // Transactions
     $("address-token-tx-list").innerHTML =
         '<div class="text-muted text-xs py-1">Loading...</div>';
@@ -252,6 +267,14 @@ function init(_ctx) {
         }
     });
 
+    $("address-token-contract-full").addEventListener("click", () => {
+        const addr = $("address-token-contract-full").dataset.full;
+        if (addr) {
+            navigator.clipboard.writeText(addr);
+            showFlash("Copied!");
+        }
+    });
+
     $("btn-address-token-back").addEventListener("click", () => {
         ctx.showAddressDetail();
     });

src/shared/transactions.js

@@ -39,10 +39,15 @@ function parseTx(tx, addrLower) {
         }
         // Map known DEX methods to "Swap" for cleaner display
         const SWAP_METHODS = new Set([
-            "execute", "swap", "swapExactTokensForTokens",
-            "swapTokensForExactTokens", "swapExactETHForTokens",
-            "swapTokensForExactETH", "swapExactTokensForETH",
-            "swapETHForExactTokens", "multicall",
+            "execute",
+            "swap",
+            "swapExactTokensForTokens",
+            "swapTokensForExactTokens",
+            "swapExactETHForTokens",
+            "swapTokensForExactETH",
+            "swapExactTokensForETH",
+            "swapETHForExactTokens",
+            "multicall",
         ]);
         const label = SWAP_METHODS.has(method)
             ? "Swap"