fix: the transaction detail screen decodes a token transfer against the token contract (closes #515)

The screen decoded a transaction's data against the history entry's `to`,
which for a token transfer row is the transfer's recipient. The decoded
Token line named the recipient, and the amount read "decimals unknown" for
a token the wallet tracks. It now decodes against the address the
explorer's answer for that transaction says it was sent to, which is the
right address for every kind of row. tests/tokenTransferDetail.test.js
opens a row made by the real history parser and checks the Token,
Recipient and Amount lines.

Model: opus-5-5

src/popup/views/transactionDetail.js

@@ -183,7 +183,7 @@ function render() {
         if (el) el.classList.add("hidden");
     }
 
-    loadFullTxDetails(tx.hash, tx.to, tx.chainId);
+    loadFullTxDetails(tx.hash, tx.chainId);
 
     const isoStr = isoDate(tx.timestamp);
     $("tx-detail-time").innerHTML =
@@ -291,7 +291,7 @@ function populateOnChainDetails(txData, chainId) {
     }
 }
 
-async function loadFullTxDetails(txHash, toAddress, chainId) {
+async function loadFullTxDetails(txHash, chainId) {
     const section = $("tx-detail-calldata-section");
     const actionEl = $("tx-detail-calldata-action");
     const detailsEl = $("tx-detail-calldata-details");
@@ -313,7 +313,10 @@ async function loadFullTxDetails(txHash, toAddress, chainId) {
         const inputData = txData.raw_input || txData.input || null;
         if (!inputData || inputData === "0x") return;
 
-        const decoded = decodeCalldata(inputData, toAddress || "");
+        // Decoded against the address the transaction was sent to, as the
+        // explorer reports it, not the history entry's `to`: for a token
+        // transfer that is the transfer's recipient, not the token contract.
+        const decoded = decodeCalldata(inputData, txData.to?.hash || "");
         if (decoded) {
             // Render decoded calldata matching approval view style
             actionEl.textContent = decoded.name;