Implement personal_sign and eth_signTypedData_v4 message signing

Replace stub error handlers with full approval flow for personal_sign,
eth_sign, eth_signTypedData_v4, and eth_signTypedData. Uses toolbar
popup only (no fallback window) and keeps sign approvals pending across
popup close/reopen cycles so the user can respond via the toolbar icon.

src/shared/tokenList.js

@@ -10,6 +10,11 @@ const { debugFetch } = require("./log");
 const COINDESK_API = "https://data-api.coindesk.com/index/cc/v1/latest/tick";
 
 const TOKENS = [
+    {
+        address: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
+        symbol: "WETH",
+        decimals: 18,
+    },
     {
         address: "0xdAC17F958D2ee523a2206206994597C13D831ec7",
         symbol: "USDT",

src/shared/uniswap.js

@@ -0,0 +1,333 @@
+// Decode Uniswap Universal Router execute() calldata into human-readable
+// swap details.  Designed to be extended with other DEX decoders later.
+
+const { Interface, AbiCoder, getBytes, formatUnits } = require("ethers");
+const { TOKEN_BY_ADDRESS } = require("./tokenList");
+
+const coder = AbiCoder.defaultAbiCoder();
+
+const ROUTER_IFACE = new Interface([
+    "function execute(bytes commands, bytes[] inputs, uint256 deadline)",
+]);
+
+// Universal Router command IDs (lower 5 bits of each command byte)
+const COMMAND_NAMES = {
+    0x00: "V3 Swap (Exact In)",
+    0x01: "V3 Swap (Exact Out)",
+    0x02: "Permit2 Transfer",
+    0x03: "Permit2 Permit Batch",
+    0x04: "Sweep",
+    0x05: "Transfer",
+    0x06: "Pay Portion",
+    0x08: "V2 Swap (Exact In)",
+    0x09: "V2 Swap (Exact Out)",
+    0x0a: "Permit2 Permit",
+    0x0b: "Wrap ETH",
+    0x0c: "Unwrap WETH",
+    0x0d: "Permit2 Transfer Batch",
+    0x0e: "Balance Check",
+    0x10: "V4 Swap",
+    0x11: "V3 Position Mgr Permit",
+    0x12: "V3 Position Mgr Call",
+    0x13: "V4 Initialize Pool",
+    0x14: "V4 Position Mgr Call",
+    0x21: "Execute Sub-Plan",
+};
+
+function formatAmount(raw, decimals) {
+    const parts = formatUnits(raw, decimals).split(".");
+    if (parts.length === 1) return parts[0] + ".0000";
+    const dec = (parts[1] + "0000").slice(0, 4);
+    return parts[0] + "." + dec;
+}
+
+function tokenInfo(address) {
+    if (!address || address === "0x0000000000000000000000000000000000000000") {
+        return { symbol: "ETH", decimals: 18, address: null };
+    }
+    const t = TOKEN_BY_ADDRESS.get(address.toLowerCase());
+    if (t) return { symbol: t.symbol, decimals: t.decimals, address };
+    return { symbol: null, decimals: 18, address };
+}
+
+// Decode PERMIT2_PERMIT (command 0x0a) input bytes.
+// ABI: ((address token, uint160 amount, uint48 expiration, uint48 nonce),
+//        address spender, uint256 sigDeadline), bytes signature
+function decodePermit2(input) {
+    try {
+        const d = coder.decode(
+            [
+                "tuple(tuple(address,uint160,uint48,uint48),address,uint256)",
+                "bytes",
+            ],
+            input,
+        );
+        return { token: d[0][0][0], amount: d[0][0][1], spender: d[0][1] };
+    } catch {
+        return null;
+    }
+}
+
+// Decode BALANCE_CHECK_ERC20 (command 0x0e) input bytes.
+// ABI: (address owner, address token, uint256 minBalance)
+function decodeBalanceCheck(input) {
+    try {
+        const d = coder.decode(["address", "address", "uint256"], input);
+        return { owner: d[0], token: d[1], minBalance: d[2] };
+    } catch {
+        return null;
+    }
+}
+
+// Decode V2_SWAP_EXACT_IN (command 0x08) input bytes.
+// ABI: (address recipient, uint256 amountIn, uint256 amountOutMin,
+//        address[] path, bool payerIsUser)
+function decodeV2SwapExactIn(input) {
+    try {
+        const d = coder.decode(
+            ["address", "uint256", "uint256", "address[]", "bool"],
+            input,
+        );
+        return {
+            amountIn: d[1],
+            amountOutMin: d[2],
+            tokenIn: d[3][0],
+            tokenOut: d[3][d[3].length - 1],
+        };
+    } catch {
+        return null;
+    }
+}
+
+// Decode V2_SWAP_EXACT_OUT (command 0x09) input bytes.
+// ABI: (address recipient, uint256 amountOut, uint256 amountInMax,
+//        address[] path, bool payerIsUser)
+function decodeV2SwapExactOut(input) {
+    try {
+        const d = coder.decode(
+            ["address", "uint256", "uint256", "address[]", "bool"],
+            input,
+        );
+        return {
+            amountOut: d[1],
+            amountInMax: d[2],
+            tokenIn: d[3][0],
+            tokenOut: d[3][d[3].length - 1],
+        };
+    } catch {
+        return null;
+    }
+}
+
+// Decode V3 swap path (packed: token(20) + fee(3) + token(20) ...)
+function decodeV3Path(pathHex) {
+    const hex = pathHex.startsWith("0x") ? pathHex.slice(2) : pathHex;
+    if (hex.length < 40) return null;
+    const tokenIn = "0x" + hex.slice(0, 40);
+    const tokenOut = "0x" + hex.slice(-40);
+    return { tokenIn, tokenOut };
+}
+
+// Decode V3_SWAP_EXACT_IN (command 0x00) input bytes.
+// ABI: (address recipient, uint256 amountIn, uint256 amountOutMin,
+//        bytes path, bool payerIsUser)
+function decodeV3SwapExactIn(input) {
+    try {
+        const d = coder.decode(
+            ["address", "uint256", "uint256", "bytes", "bool"],
+            input,
+        );
+        const path = decodeV3Path(d[3]);
+        if (!path) return null;
+        return {
+            amountIn: d[1],
+            amountOutMin: d[2],
+            tokenIn: path.tokenIn,
+            tokenOut: path.tokenOut,
+        };
+    } catch {
+        return null;
+    }
+}
+
+// Decode WRAP_ETH (command 0x0b) input bytes.
+// ABI: (address recipient, uint256 amount)
+function decodeWrapEth(input) {
+    try {
+        const d = coder.decode(["address", "uint256"], input);
+        return { amount: d[1] };
+    } catch {
+        return null;
+    }
+}
+
+// Try to decode a Universal Router execute() call.
+// Returns { name, description, details } matching the format used by
+// the approval UI, or null if the calldata is not a recognised execute().
+function decode(data, toAddress) {
+    try {
+        const parsed = ROUTER_IFACE.parseTransaction({ data });
+        if (!parsed) return null;
+
+        const commandsBytes = getBytes(parsed.args[0]);
+        const inputs = parsed.args[1];
+        const deadline = parsed.args[2];
+
+        let inputToken = null;
+        let inputAmount = null;
+        let outputToken = null;
+        let minOutput = null;
+        let hasUnwrapWeth = false;
+        const commandNames = [];
+
+        for (let i = 0; i < commandsBytes.length; i++) {
+            const cmdId = commandsBytes[i] & 0x1f;
+            commandNames.push(
+                COMMAND_NAMES[cmdId] ||
+                    "Command 0x" + cmdId.toString(16).padStart(2, "0"),
+            );
+
+            try {
+                if (cmdId === 0x0a) {
+                    const p = decodePermit2(inputs[i]);
+                    if (p) {
+                        inputToken = p.token;
+                        inputAmount = p.amount;
+                    }
+                }
+
+                if (cmdId === 0x0e) {
+                    const b = decodeBalanceCheck(inputs[i]);
+                    if (b) {
+                        outputToken = b.token;
+                        minOutput = b.minBalance;
+                    }
+                }
+
+                if (cmdId === 0x00) {
+                    const s = decodeV3SwapExactIn(inputs[i]);
+                    if (s) {
+                        if (!inputToken) inputToken = s.tokenIn;
+                        if (!outputToken) outputToken = s.tokenOut;
+                        if (!inputAmount) inputAmount = s.amountIn;
+                        if (!minOutput) minOutput = s.amountOutMin;
+                    }
+                }
+
+                if (cmdId === 0x08) {
+                    const s = decodeV2SwapExactIn(inputs[i]);
+                    if (s) {
+                        if (!inputToken) inputToken = s.tokenIn;
+                        if (!outputToken) outputToken = s.tokenOut;
+                        if (!inputAmount) inputAmount = s.amountIn;
+                        if (!minOutput) minOutput = s.amountOutMin;
+                    }
+                }
+
+                if (cmdId === 0x0b) {
+                    const w = decodeWrapEth(inputs[i]);
+                    if (w && !inputToken) {
+                        inputToken =
+                            "0x0000000000000000000000000000000000000000";
+                        inputAmount = w.amount;
+                    }
+                }
+
+                if (cmdId === 0x0c) {
+                    hasUnwrapWeth = true;
+                }
+            } catch {
+                // Skip commands we can't decode
+            }
+        }
+
+        // Resolve token info
+        const inInfo = tokenInfo(inputToken);
+        const outInfo = hasUnwrapWeth
+            ? { symbol: "ETH", decimals: 18, address: null }
+            : tokenInfo(outputToken);
+
+        const inSymbol = inInfo.symbol;
+        const outSymbol = outInfo.symbol;
+
+        const name =
+            inSymbol && outSymbol
+                ? "Swap " + inSymbol + " \u2192 " + outSymbol
+                : "Uniswap Swap";
+
+        const details = [];
+
+        details.push({
+            label: "Protocol",
+            value: "Uniswap Universal Router",
+            address: toAddress,
+        });
+
+        if (inputToken && inInfo.address) {
+            const label = inSymbol
+                ? inSymbol + " (" + inputToken + ")"
+                : inputToken;
+            details.push({
+                label: "Token In",
+                value: label,
+                address: inputToken,
+                isToken: true,
+            });
+        } else if (inSymbol === "ETH") {
+            details.push({ label: "Token In", value: "ETH (native)" });
+        }
+
+        if (inputAmount !== null && inputAmount !== undefined) {
+            const maxUint160 = BigInt(
+                "0xffffffffffffffffffffffffffffffffffffffff",
+            );
+            const amountStr =
+                inputAmount >= maxUint160
+                    ? "Unlimited"
+                    : formatAmount(inputAmount, inInfo.decimals) +
+                      (inSymbol ? " " + inSymbol : "");
+            details.push({ label: "Amount", value: amountStr });
+        }
+
+        if (outSymbol) {
+            if (outInfo.address) {
+                const label = outSymbol
+                    ? outSymbol + " (" + outputToken + ")"
+                    : outputToken;
+                details.push({
+                    label: "Token Out",
+                    value: label,
+                    address: outputToken,
+                    isToken: true,
+                });
+            } else {
+                details.push({ label: "Token Out", value: outSymbol });
+            }
+        }
+
+        if (minOutput !== null && minOutput !== undefined) {
+            const minStr =
+                formatAmount(minOutput, outInfo.decimals) +
+                (outSymbol ? " " + outSymbol : "");
+            details.push({ label: "Min. received", value: minStr });
+        }
+
+        details.push({ label: "Steps", value: commandNames.join(" \u2192 ") });
+
+        const deadlineDate = new Date(Number(deadline) * 1000);
+        details.push({
+            label: "Deadline",
+            value: deadlineDate.toISOString().replace("T", " ").slice(0, 19),
+        });
+
+        return {
+            name,
+            description: "Swap via Uniswap Universal Router",
+            details,
+        };
+    } catch {
+        return null;
+    }
+}
+
+module.exports = { decode };