fix: say a contract creation has no recipient instead of a blank line (closes #250)

A transaction with no `to` showed a blank address, with a colour dot whose
colour was `undefined`, on the wait, success and error screens, the
transaction detail view and the history rows on Home, AddressDetail and
AddressToken. The approval screen showed "(contract creation)".

All of them now say "This transaction creates a new contract. It has no
recipient." The three history lists draw a row's counterparty lines through
one helper in helpers.js. A transaction with a real `to` is unchanged. The
new test drives each screen and list both ways.

Model: opus-5-5

src/popup/views/home.js

@@ -6,6 +6,7 @@ const {
     isoDate,
     timeAgo,
     addressDotHtml,
+    txCounterpartyHtml,
     addressTitle,
     escapeHtml,
     displaySymbol,
@@ -122,16 +123,13 @@ function renderHomeTxList(ctx) {
         // names it on the line above rather than replacing it.
         const title = addressTitle(counterparty, state.wallets);
         const titleStr = title ? escapeHtml(title) : "";
-        const addrStr = escapeHtml(counterparty);
-        const dot = addressDotHtml(counterparty);
         const err = tx.isError ? " (failed)" : "";
         const opacity = tx.isError ? " opacity:0.5;" : "";
         const ago = escapeHtml(timeAgo(tx.timestamp));
         const iso = escapeHtml(isoDate(tx.timestamp));
         html += `<div class="home-tx-row py-2 border-b border-border-light text-xs cursor-pointer hover:bg-hover" data-tx="${i}" style="${opacity}">`;
         html += `<div class="flex justify-between"><span class="text-muted" title="${iso}">${ago}</span><span>${dirLabel}${err}</span></div>`;
-        html += `<div class="flex justify-between"><span class="flex items-center">${dot}${titleStr}</span><span>${amountStr}</span></div>`;
-        html += `<div class="am-address">${addrStr}</div>`;
+        html += txCounterpartyHtml(counterparty, titleStr, amountStr);
         html += `</div>`;
         i++;
     }