Fix layout shift from async USD prices and token balances

Reserve vertical space with min-height and   placeholders for all
elements populated by async data: per-address USD totals, ETH price
display, token balance containers, and total value sub-line.  Prevents
buttons and click targets from moving when price API responds.

src/popup/index.html

@@ -274,11 +274,15 @@
                 </div>
                 <div
                     id="address-usd-total"
-                    class="text-xs text-muted mb-3 text-right"
-                ></div>
+                    class="text-xs text-muted mb-3 text-right min-h-[1rem]"
+                >
+                    &nbsp;
+                </div>
                 <!-- balances -->
                 <div class="border-b border-border-light pb-2 mb-2">
-                    <div id="address-balances"></div>
+                    <div id="address-balances" class="min-h-[1.25rem]">
+                        &nbsp;
+                    </div>
                 </div>
 
                 <!-- actions -->
@@ -343,11 +347,15 @@
                 </div>
                 <div
                     id="address-token-usd-total"
-                    class="text-xs text-muted mb-3 text-right"
-                ></div>
+                    class="text-xs text-muted mb-3 text-right min-h-[1rem]"
+                >
+                    &nbsp;
+                </div>
                 <!-- single token balance -->
                 <div class="border-b border-border-light pb-2 mb-2">
-                    <div id="address-token-balance"></div>
+                    <div id="address-token-balance" class="min-h-[1.25rem]">
+                        &nbsp;
+                    </div>
                 </div>
 
                 <!-- actions -->

src/popup/views/addressDetail.js

@@ -54,7 +54,8 @@ function show() {
     const addrLink = etherscanAddressLink(addr.address);
     $("address-etherscan-link").innerHTML =
         `<a href="${addrLink}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-    $("address-usd-total").textContent = formatUsd(getAddressValueUsd(addr));
+    const usdTotal = formatUsd(getAddressValueUsd(addr));
+    $("address-usd-total").innerHTML = usdTotal || "&nbsp;";
     const ensEl = $("address-ens");
     if (addr.ensName) {
         ensEl.innerHTML =

src/popup/views/addressToken.js

@@ -124,7 +124,8 @@ function show() {
 
     // USD total for this token only
     const usdVal = price ? amount * price : 0;
-    $("address-token-usd-total").textContent = formatUsd(usdVal);
+    const usdStr = formatUsd(usdVal);
+    $("address-token-usd-total").innerHTML = usdStr || " ";
 
     // Single token balance line (no tokenId — not clickable here)
     $("address-token-balance").innerHTML = balanceLine(symbol, amount, price);

src/popup/views/home.js

@@ -38,13 +38,15 @@ function renderTotalValue() {
 
     const ethPrice = getPrice("ETH");
     if (priceEl) {
-        priceEl.textContent = ethPrice ? formatUsd(ethPrice) + " USD/ETH" : "";
+        priceEl.innerHTML = ethPrice
+            ? formatUsd(ethPrice) + " USD/ETH"
+            : " ";
     }
 
     const addr = findActiveAddr();
     if (!addr) {
-        el.textContent = "";
-        if (subEl) subEl.textContent = "";
+        el.innerHTML = " ";
+        if (subEl) subEl.innerHTML = " ";
         return;
     }
     const ethBal = parseFloat(addr.balance || "0");
@@ -54,8 +56,8 @@ function renderTotalValue() {
 
     if (subEl) {
         const totalUsd = getAddressValueUsd(addr);
-        subEl.textContent =
-            totalUsd !== null ? "Total: " + formatUsd(totalUsd) : "";
+        subEl.innerHTML =
+            totalUsd !== null ? "Total: " + formatUsd(totalUsd) : " ";
     }
 }
 
@@ -276,7 +278,7 @@ function render(ctx) {
             html += `<span class="flex-shrink-0 ml-1">${infoBtn}</span>`;
             html += `</div>`;
             const addrUsd = formatUsd(getAddressValueUsd(addr));
-            html += `<div class="text-xs text-muted text-right">${addrUsd}</div>`;
+            html += `<div class="text-xs text-muted text-right min-h-[1rem]">${addrUsd || "&nbsp;"}</div>`;
             html += balanceLinesForAddress(
                 addr,
                 state.trackedTokens,