Show ETH price, split headline into ETH balance and total USD

Headline shows active address ETH balance with ETH-only USD value
in parentheses. Small "Total:" subtitle below includes ETH + token
values. A centered well between Send/Receive buttons and the wallet
list displays the current ETH price in USD.

src/popup/index.html

@@ -172,11 +172,12 @@
 
             <!-- ============ MAIN VIEW: ALL WALLETS & ADDRESSES ============ -->
             <div id="view-main" class="view hidden">
-                <!-- total portfolio value -->
+                <!-- active address headline -->
                 <div
                     id="total-value"
-                    class="text-2xl font-bold mb-2 min-h-[2rem]"
+                    class="text-2xl font-bold min-h-[2rem]"
                 ></div>
+                <div id="total-value-sub" class="text-xs text-muted mb-2"></div>
 
                 <!-- active address display -->
                 <div
@@ -185,7 +186,7 @@
                 ></div>
 
                 <!-- quick actions for active address -->
-                <div class="flex gap-2 mb-3">
+                <div class="flex gap-2 mb-2">
                     <button
                         id="btn-main-send"
                         class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer flex-1"
@@ -200,6 +201,12 @@
                     </button>
                 </div>
 
+                <!-- ETH price -->
+                <div
+                    id="eth-price-display"
+                    class="bg-well text-center font-bold text-xs p-1 mx-1 mb-3"
+                ></div>
+
                 <!-- wallet list -->
                 <div id="wallet-list"></div>
             </div>