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. 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

@@ -1,11 +1,16 @@
 // The approval screen for a site's Sepolia token transfer while Ethereum
-// Mainnet is active (https://git.eeqj.de/sneak/AutistMask/issues/629).
+// Mainnet is active.
 //
 // The screen named the token, and scaled its amount, from the active network's
 // tracked tokens and balances, so a token the wallet tracks on Sepolia read as
 // an unknown token with its amount in base units, and the screens after it
-// labelled the amount `?`. It now uses what the wallet knows of the tokens on
-// the network the transaction is for.
+// labelled the amount `?` (https://git.eeqj.de/sneak/AutistMask/issues/629).
+// It now uses what the wallet knows of the tokens on the network the
+// transaction is for.
+//
+// Its address links opened the active network's explorer
+// (https://git.eeqj.de/sneak/AutistMask/issues/631). They now open the
+// explorer of the network the transaction is for.
 //
 // Driven through the real approval screen, password and Confirm included,
 // against a minimal DOM stub in the shape tests/swapStatusAmount.test.js uses.
@@ -218,3 +223,28 @@ test("a token tracked and held on mainnet only is not named, and its amount is i
         '<div class="font-bold">1234500000 base units (decimals unknown)</div>',
     );
 });
+
+// The From and Contract lines, and the decoded Token and Recipient lines.
+test("every address links to the Sepolia explorer", async () => {
+    await showSepoliaTransfer();
+    const sepolia = NETWORKS.sepolia.explorerUrl;
+    expect(node("approve-tx-from").innerHTML).toContain(
+        `href="${sepolia}/address/${FROM}"`,
+    );
+    expect(node("approve-tx-to").innerHTML).toContain(
+        `href="${sepolia}/address/${TOKEN}"`,
+    );
+    expect(decodedLine("Token")).toContain(
+        `href="${sepolia}/address/${TOKEN}"`,
+    );
+    expect(decodedLine("Recipient")).toContain(
+        `href="${sepolia}/address/${RECIPIENT}"`,
+    );
+    for (const id of [
+        "approve-tx-from",
+        "approve-tx-to",
+        "approve-tx-decoded-details",
+    ]) {
+        expect(node(id).innerHTML).not.toContain(NETWORKS.mainnet.explorerUrl);
+    }
+});

tests/walletDefects.test.js

@@ -475,7 +475,7 @@ describe("every way to a signature or the private key refuses a defective wallet
                 to: RECIPIENT,
                 value: "0x0",
                 data: "0x",
-                chainId: 1,
+                chainId: "0x1",
                 nonce: 0,
                 gasLimit: "21000",
                 maxFeePerGas: "1000000000",