Use compact [ ] select button and show active address above actions

Replace [select] with [ ] to avoid wrapping the full address line.
ACTIVE label stays as-is for discoverability. Show the currently
active address (full, untruncated, with color dot) above the Send
and Receive buttons on the home screen.

src/popup/index.html

@@ -178,6 +178,12 @@
                     class="text-2xl font-bold mb-2 min-h-[2rem]"
                 ></div>
 
+                <!-- active address display -->
+                <div
+                    id="active-address-display"
+                    class="text-xs break-all mb-3"
+                ></div>
+
                 <!-- quick actions for active address -->
                 <div class="flex gap-2 mb-3">
                     <button

src/popup/views/home.js

@@ -21,12 +21,24 @@ function renderTotalValue() {
     el.textContent = formatUsd(getTotalValueUsd(state.wallets));
 }
 
+function renderActiveAddress() {
+    const el = $("active-address-display");
+    if (!el) return;
+    if (state.activeAddress) {
+        const dot = addressDotHtml(state.activeAddress);
+        el.innerHTML = dot + state.activeAddress;
+    } else {
+        el.textContent = "";
+    }
+}
+
 function render(ctx) {
     const container = $("wallet-list");
     if (state.wallets.length === 0) {
         container.innerHTML =
             '<p class="text-muted py-2">No wallets yet. Add one to get started.</p>';
         renderTotalValue();
+        renderActiveAddress();
         return;
     }
 
@@ -45,7 +57,7 @@ function render(ctx) {
             const isActive = state.activeAddress === addr.address;
             const activeHtml = isActive
                 ? `<span class="font-bold text-xs">ACTIVE</span>`
-                : `<span class="btn-select-active text-xs font-normal cursor-pointer" data-addr="${addr.address}">[<span class="underline decoration-dashed">select</span>]</span>`;
+                : `<span class="btn-select-active text-xs cursor-pointer" data-addr="${addr.address}">[ ]</span>`;
             const dot = addressDotHtml(addr.address);
             html += `<div class="text-xs font-bold">Address ${wi + 1}.${ai + 1}</div>`;
             if (addr.ensName) {
@@ -146,6 +158,7 @@ function render(ctx) {
     });
 
     renderTotalValue();
+    renderActiveAddress();
 }
 
 function selectActiveAddress() {