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/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,