fix: zero-tx warning layout shift and contract address false positive

- Reserve space for the warning upfront using visibility:hidden instead
  of display:none, preventing layout shift per README policy
- Move warning HTML to index.html as a static element rather than
  injecting dynamically
- Skip warning for contract addresses (check getCode first) since
  getTransactionCount only returns outgoing tx nonce
- Collapse reserved space when warning is not needed (address has
  history, is a contract, or on RPC error)

src/popup/index.html

@@ -577,6 +577,19 @@
                     <div id="confirm-fee-amount" class="text-xs"></div>
                 </div>
                 <div id="confirm-warnings" class="mb-2 hidden"></div>
+                <div
+                    id="confirm-recipient-warning"
+                    class="mb-2"
+                    style="visibility: hidden"
+                >
+                    <div
+                        class="border border-red-500 border-dashed p-2 text-xs font-bold text-red-500"
+                    >
+                        WARNING: The recipient address has ZERO transaction
+                        history. This may indicate a fresh or unused address.
+                        Double-check the address before sending.
+                    </div>
+                </div>
                 <div
                     id="confirm-errors"
                     class="mb-2 border border-border border-dashed p-2 hidden"

src/popup/views/approval.js

@@ -172,6 +172,8 @@ function showTxApproval(details) {
     // If this is an ERC-20 call, try to extract the real recipient and amount
     const decoded = decodeCalldata(details.txParams.data, toAddr || "");
     if (decoded && decoded.details) {
+        let decodedTokenAddr = null;
+        let decodedTokenSymbol = null;
         for (const d of decoded.details) {
             if (d.label === "Recipient" && d.address) {
                 pendingTxDetails.to = d.address;
@@ -179,10 +181,20 @@ function showTxApproval(details) {
             if (d.label === "Amount") {
                 pendingTxDetails.amount = d.rawValue || d.value;
             }
+            if (d.label === "Token In" && d.isToken && d.address) {
+                const t = TOKEN_BY_ADDRESS.get(d.address.toLowerCase());
+                if (t) {
+                    decodedTokenAddr = d.address;
+                    decodedTokenSymbol = t.symbol;
+                }
+            }
         }
         if (token) {
             pendingTxDetails.token = toAddr;
             pendingTxDetails.tokenSymbol = token.symbol;
+        } else if (decodedTokenAddr) {
+            pendingTxDetails.token = decodedTokenAddr;
+            pendingTxDetails.tokenSymbol = decodedTokenSymbol;
         }
     }
 

src/popup/views/confirmTx.js

@@ -243,7 +243,14 @@ function show(txInfo) {
     state.viewData = { pendingTx: txInfo };
     showView("confirm-tx");
 
+    // Reset recipient warning: reserve space (visibility:hidden) while
+    // the async check runs, preventing layout shift per README policy.
+    const recipientWarning = $("confirm-recipient-warning");
+    recipientWarning.style.display = "";
+    recipientWarning.style.visibility = "hidden";
+
     estimateGas(txInfo);
+    checkRecipientHistory(txInfo);
 }
 
 async function estimateGas(txInfo) {
@@ -286,6 +293,34 @@ async function estimateGas(txInfo) {
     }
 }
 
+async function checkRecipientHistory(txInfo) {
+    const el = $("confirm-recipient-warning");
+    try {
+        const provider = getProvider(state.rpcUrl);
+        // Skip warning for contract addresses — they may legitimately
+        // have zero outgoing transactions (getTransactionCount returns
+        // the nonce, i.e. sent-tx count only).
+        const code = await provider.getCode(txInfo.to);
+        if (code && code !== "0x") {
+            // Contract address — hide the reserved space entirely
+            el.style.display = "none";
+            return;
+        }
+        const txCount = await provider.getTransactionCount(txInfo.to);
+        if (txCount === 0) {
+            el.style.visibility = "visible";
+        } else {
+            // Address has history — collapse the reserved space
+            el.style.display = "none";
+        }
+    } catch (e) {
+        log.errorf("recipient history check failed:", e.message);
+        // On error, collapse the reserved space rather than showing a
+        // false warning or leaving an empty gap
+        el.style.display = "none";
+    }
+}
+
 function init(ctx) {
     $("btn-confirm-send").addEventListener("click", async () => {
         const password = $("confirm-tx-password").value;

src/popup/views/txStatus.js

@@ -43,10 +43,11 @@ function toAddressHtml(address) {
     if (title) {
         return (
             `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>` +
-            `<div class="break-all">${escapeHtml(address)}${extLink}</div>`
+            `<div class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(address)}">${escapeHtml(address)}</div>` +
+            extLink
         );
     }
-    return `<div class="flex items-center">${dot}<span class="break-all">${escapeHtml(address)}</span>${extLink}</div>`;
+    return `<div class="flex items-center">${dot}<span class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(address)}">${escapeHtml(address)}</span>${extLink}</div>`;
 }
 
 function txHashHtml(hash) {
@@ -139,7 +140,7 @@ function etherscanTokenLink(address) {
 
 function decodedDetailsHtml(decoded) {
     if (!decoded || !decoded.details) return "";
-    let html = "";
+    let html = `<div class="border border-border border-dashed p-2 mb-3">`;
     if (decoded.name) {
         html += `<div class="mb-2"><div class="text-xs text-muted mb-1">Action</div>`;
         html += `<div class="font-bold">${escapeHtml(decoded.name)}</div></div>`;
@@ -164,20 +165,36 @@ function decodedDetailsHtml(decoded) {
         }
         html += `</div>`;
     }
+    html += `</div>`;
     return html;
 }
 
 function renderSuccess() {
     const d = state.viewData;
     if (!d || !d.hash) return;
-    $("success-tx-summary").textContent = d.amount + " " + d.symbol;
-    $("success-tx-to").innerHTML = toAddressHtml(d.to);
+
+    const hasDecoded = d.decoded && d.decoded.details;
+
+    // When decoded details are present, the Amount and To are already
+    // shown inside the decoded well — hide the top-level duplicates.
+    const summarySection = $("success-tx-summary").parentElement;
+    const toSection = $("success-tx-to").parentElement;
+    if (hasDecoded) {
+        summarySection.classList.add("hidden");
+        toSection.classList.add("hidden");
+    } else {
+        summarySection.classList.remove("hidden");
+        toSection.classList.remove("hidden");
+        $("success-tx-summary").textContent = d.amount + " " + d.symbol;
+        $("success-tx-to").innerHTML = toAddressHtml(d.to);
+    }
+
     $("success-tx-block").textContent = String(d.blockNumber);
     $("success-tx-hash").innerHTML = txHashHtml(d.hash);
 
     // Show decoded calldata details if present
     const decodedEl = $("success-tx-decoded");
-    if (decodedEl && d.decoded) {
+    if (decodedEl && hasDecoded) {
         decodedEl.innerHTML = decodedDetailsHtml(d.decoded);
         decodedEl.classList.remove("hidden");
     } else if (decodedEl) {

src/shared/uniswap.js

@@ -445,12 +445,18 @@ function decode(data, toAddress) {
             const maxUint160 = BigInt(
                 "0xffffffffffffffffffffffffffffffffffffffff",
             );
-            const amountStr =
-                inputAmount >= maxUint160
-                    ? "Unlimited"
-                    : formatAmount(inputAmount, inInfo.decimals) +
-                      (inSymbol ? " " + inSymbol : "");
-            details.push({ label: "Amount", value: amountStr });
+            const isUnlimited = inputAmount >= maxUint160;
+            const amountRaw = isUnlimited
+                ? "Unlimited"
+                : formatAmount(inputAmount, inInfo.decimals);
+            const amountStr = isUnlimited
+                ? "Unlimited"
+                : amountRaw + (inSymbol ? " " + inSymbol : "");
+            details.push({
+                label: "Amount",
+                value: amountStr,
+                rawValue: amountRaw,
+            });
         }
 
         if (outSymbol) {