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/home.js

@@ -10,13 +10,10 @@ const {
     addressTitle,
     escapeHtml,
     truncateMiddle,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = require("./helpers");
-const {
-    state,
-    saveState,
-    currentAddress,
-    currentNetwork,
-} = require("../../shared/state");
+const { state, saveState, currentAddress } = require("../../shared/state");
 const {
     updateSendBalance,
     renderSendTokenSelect,
@@ -74,28 +71,12 @@ function renderTotalValue() {
     }
 }
 
-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 renderActiveAddress() {
     const el = $("active-address-display");
     if (!el) return;
     if (state.activeAddress) {
-        const addr = state.activeAddress;
-        const dot = addressDotHtml(addr);
-        const link = `${currentNetwork().explorerUrl}/address/${addr}`;
-        el.innerHTML =
-            `<span class="underline decoration-dashed cursor-pointer" id="active-addr-copy">${dot}${escapeHtml(addr)}</span>` +
-            `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-        $("active-addr-copy").addEventListener("click", (e) => {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
-        });
+        el.innerHTML = renderAddressHtml(state.activeAddress);
+        attachCopyHandlers(el);
     } else {
         el.textContent = "";
     }