Classify transactions by decoded calldata in history

Use the shared decodeCalldata module to detect Uniswap swaps,
token approvals, and unknown contract calls in parseTx. Swaps
now show 'Swap TOKEN_A → TOKEN_B' instead of 'Sent'. Unknown
contract calls show 'Contract Call'. Raw input and decoded
data are passed through for the detail view.

src/shared/transactions.js

@@ -9,6 +9,7 @@
 const { formatEther, formatUnits } = require("ethers");
 const { log, debugFetch } = require("./log");
 const { KNOWN_SYMBOLS, TOKEN_BY_ADDRESS } = require("./tokenList");
+const { decodeCalldata } = require("./decodeCalldata");
 
 function formatTxValue(val) {
     const parts = val.split(".");
@@ -23,6 +24,7 @@ function parseTx(tx, addrLower) {
     const rawWei = tx.value || "0";
     const toIsContract = tx.to?.is_contract || false;
     const method = tx.method || null;
+    const rawInput = tx.raw_input || null;
 
     // For contract calls, produce a meaningful label instead of "0.0000 ETH"
     let symbol = "ETH";
@@ -32,14 +34,41 @@ function parseTx(tx, addrLower) {
     let rawUnit = "wei";
     let direction = from.toLowerCase() === addrLower ? "sent" : "received";
     let directionLabel = direction === "sent" ? "Sent" : "Received";
-    if (toIsContract && method && method !== "transfer") {
-        const token = TOKEN_BY_ADDRESS.get(to.toLowerCase());
-        if (token) {
-            symbol = token.symbol;
+    let decoded = null;
+
+    if (rawInput && rawInput !== "0x" && rawInput.length >= 10) {
+        decoded = decodeCalldata(rawInput, to);
+        if (decoded) {
+            // Uniswap swaps: show "Swap" with token pair
+            if (decoded.name && decoded.name.startsWith("Swap")) {
+                direction = "contract";
+                directionLabel = decoded.name;
+                value = "";
+                exactValue = "";
+                rawAmount = "";
+                rawUnit = "";
+            } else if (decoded.name === "Token Approval") {
+                direction = "contract";
+                directionLabel = "Approve";
+                value = "";
+                exactValue = "";
+                rawAmount = "";
+                rawUnit = "";
+            }
+            // Token Transfer: keep as Sent/Received (handled by token transfer overlay)
+        } else if (toIsContract && method && method !== "transfer") {
+            // Unknown contract call
+            direction = "contract";
+            directionLabel = "Contract Call";
+            value = "";
+            exactValue = "";
+            rawAmount = "";
+            rawUnit = "";
         }
-        const label = method.charAt(0).toUpperCase() + method.slice(1);
+    } else if (toIsContract && method && method !== "transfer") {
+        // Contract call without raw input data
         direction = "contract";
-        directionLabel = label;
+        directionLabel = "Contract Call";
         value = "";
         exactValue = "";
         rawAmount = "";
@@ -65,6 +94,8 @@ function parseTx(tx, addrLower) {
         holders: null,
         isContractCall: toIsContract,
         method: method,
+        rawInput: rawInput,
+        decoded: decoded,
     };
 }