fix: TxApproval links addresses to the explorer of the transaction's network (closes #631)

TxApproval built its From, Contract and decoded-action address links for
the active network, so a Sepolia transaction reviewed with mainnet active
linked to the mainnet explorer. approvalAddressHtml() now takes the
transaction's chain id and passes it to renderAddressHtml(), as SuccessTx
and ErrorTx do. A chain id that names no network has no explorer, so its
address lines are drawn without a link and the screen still shows. SignApproval
and SiteApproval still link for the active network. The walletDefects
fixture's numeric chain id, which names no network, is now the hex string
the background sends.

Model: opus-5-5

tests/approvalTokenNetwork.test.js

@@ -115,7 +115,7 @@ function decodedLine(label) {
 // `tokenBalances` there, for the site's transaction sending TRANSFER_DATA to
 // the token, on Sepolia unless `chainId` names another chain. Confirm answers
 // the signed transaction with a failure, which leads to the error screen.
-async function showTokenTransfer(
+async function showSepoliaTransfer(
     tokenBalances = [],
     chainId = NETWORKS.sepolia.chainId,
 ) {
@@ -191,7 +191,7 @@ describe("a token tracked on Sepolia only", () => {
     });
 
     test("is named on the Contract line and the decoded Token line, with its amount at its scale", async () => {
-        await showTokenTransfer();
+        await showSepoliaTransfer();
         expect(node("approve-tx-to").innerHTML).toContain(
             '<div class="font-bold mb-1">TDOL</div>',
         );
@@ -204,7 +204,7 @@ describe("a token tracked on Sepolia only", () => {
     });
 
     test("labels the amount on the error screen that follows", async () => {
-        await showTokenTransfer();
+        await showSepoliaTransfer();
         await confirm();
         expect(state.currentView).toBe("error-tx");
         expect(node("error-tx-summary").textContent).toBe("1234.5000 TDOL");
@@ -215,7 +215,7 @@ describe("a token tracked on Sepolia only", () => {
 // tracks and holds there names nothing on Sepolia.
 test("a token tracked and held on mainnet only is not named, and its amount is in base units", async () => {
     state.trackedTokens = [{ address: TOKEN, symbol: "MDOL", decimals: 18 }];
-    await showTokenTransfer([
+    await showSepoliaTransfer([
         { address: TOKEN, symbol: "MDOL", decimals: 18, balance: "1.0" },
     ]);
     expect(node("approve-tx-to").innerHTML).not.toContain("MDOL");
@@ -229,7 +229,7 @@ test("a token tracked and held on mainnet only is not named, and its amount is i
 
 // The From and Contract lines, and the decoded Token and Recipient lines.
 test("every address links to the Sepolia explorer", async () => {
-    await showTokenTransfer();
+    await showSepoliaTransfer();
     const sepolia = NETWORKS.sepolia.explorerUrl;
     expect(node("approve-tx-from").innerHTML).toContain(
         `href="${sepolia}/address/${FROM}"`,
@@ -254,7 +254,7 @@ test("every address links to the Sepolia explorer", async () => {
 
 // Chain id 1337 names no network here, so it has no explorer to link to.
 test("a transaction on a chain id that names no network is shown with no address links", async () => {
-    await showTokenTransfer([], "0x539");
+    await showSepoliaTransfer([], "0x539");
     expect(state.currentView).toBe("approve-tx");
     expect(node("approve-tx-network").textContent).toBe(
         "Unknown network (chain id 1337)",