fix: unify address display with shared renderAddressHtml utility

All address rendering now uses a single renderAddressHtml() function in
helpers.js that produces consistent output everywhere:
- Color dot (deterministic from address)
- Full address with dashed-underline click-to-copy affordance
- Etherscan external link icon

Refactored all callsites across 9 view files:
- approval.js: approvalAddressHtml now delegates to renderAddressHtml,
  added attachCopyHandlers for click-to-copy on approve-tx/sign/site views
- confirmTx.js: confirmAddressHtml uses renderAddressHtml, token contract
  address uses renderAddressHtml with attachCopyHandlers
- txStatus.js: toAddressHtml delegates to renderAddressHtml
- transactionDetail.js: txAddressHtml delegates to renderAddressHtml,
  decoded calldata addresses use renderAddressHtml
- home.js: active address display uses renderAddressHtml
- send.js: from-address display uses renderAddressHtml
- receive.js: address block uses formatAddressHtml (which delegates to
  renderAddressHtml), removed separate etherscan link element
- addressDetail.js: address line uses renderAddressHtml, export-privkey
  address uses renderAddressHtml
- addressToken.js: address line and contract info use renderAddressHtml

Also consolidated:
- EXT_ICON SVG constant moved to helpers.js (removed 6 duplicates)
- copyableHtml() moved to helpers.js (removed duplicate in transactionDetail)
- etherscanLinkHtml() moved to helpers.js (removed duplicates)
- attachCopyHandlers() moved to helpers.js (removed duplicate in txStatus)
- Removed unused local functions (etherscanTokenLink, etherscanAddressLink)
- Cleaned up unused imports across all files

closes #97

src/popup/views/receive.js

@@ -5,17 +5,11 @@ const {
     flashCopyFeedback,
     formatAddressHtml,
     addressTitle,
+    attachCopyHandlers,
 } = require("./helpers");
 const { state, currentAddress, currentNetwork } = require("../../shared/state");
 const QRCode = require("qrcode");
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 function show() {
     const addr = currentAddress();
     const address = addr ? addr.address : "";
@@ -25,11 +19,8 @@ function show() {
         ? formatAddressHtml(address, ensName, null, title)
         : "";
     $("receive-address-block").dataset.full = address;
-    const net = currentNetwork();
-    const link = address ? `${net.explorerUrl}/address/${address}` : "";
-    $("receive-etherscan-link").innerHTML = link
-        ? `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`
-        : "";
+    // Etherscan link is now included in formatAddressHtml via renderAddressHtml
+    $("receive-etherscan-link").innerHTML = "";
     if (address) {
         QRCode.toCanvas($("receive-qr"), address, {
             width: 200,
@@ -62,18 +53,10 @@ function show() {
         warningEl.style.visibility = "hidden";
     }
     showView("receive");
+    attachCopyHandlers("view-receive");
 }
 
 function init(ctx) {
-    $("receive-address-block").addEventListener("click", (e) => {
-        const addr = $("receive-address-block").dataset.full;
-        if (addr) {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
-        }
-    });
-
     $("btn-receive-copy").addEventListener("click", () => {
         const addr = $("receive-address-block").dataset.full;
         if (addr) {