feat: add WalletConnect v2 integration for mobile wallet connection

- Add @walletconnect/sign-client for dApp-side WC v2 support
- Create walletconnect-service.ts with session management and Signer adapter
- Create WalletConnectModal.tsx with QR code display
- Update PezkuwiContext with connectWalletConnect(), session restore, walletSource tracking
- Update WalletContext signing router: mobile → WalletConnect → extension
- Update WalletModal with "Connect with pezWallet (Mobile)" button
- Move WalletConnect projectId to env variable
- Fix vite build: disable assetsInclude for JSON (crypto-browserify compat)

web/src/components/wallet/WalletConnectModal.tsx

@@ -0,0 +1,158 @@
+import React, { useEffect, useState, useCallback } from 'react';
+import { useTranslation } from 'react-i18next';
+import { Smartphone, Loader2, CheckCircle, XCircle } from 'lucide-react';
+import QRCode from 'qrcode';
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
+import { usePezkuwi } from '@/contexts/PezkuwiContext';
+
+interface WalletConnectModalProps {
+  isOpen: boolean;
+  onClose: () => void;
+}
+
+type ConnectionState = 'generating' | 'waiting' | 'connected' | 'error';
+
+export const WalletConnectModal: React.FC<WalletConnectModalProps> = ({ isOpen, onClose }) => {
+  const { t } = useTranslation();
+  const { connectWalletConnect, selectedAccount, wcPeerName } = usePezkuwi();
+  const [qrDataUrl, setQrDataUrl] = useState<string>('');
+  const [connectionState, setConnectionState] = useState<ConnectionState>('generating');
+  const [errorMsg, setErrorMsg] = useState<string>('');
+
+  const startConnection = useCallback(async () => {
+    setConnectionState('generating');
+    setErrorMsg('');
+
+    try {
+      const uri = await connectWalletConnect();
+
+      // Generate QR code as data URL
+      const dataUrl = await QRCode.toDataURL(uri, {
+        width: 300,
+        margin: 2,
+        color: {
+          dark: '#000000',
+          light: '#ffffff',
+        },
+      });
+
+      setQrDataUrl(dataUrl);
+      setConnectionState('waiting');
+    } catch (err) {
+      setConnectionState('error');
+      setErrorMsg(err instanceof Error ? err.message : 'Connection failed');
+    }
+  }, [connectWalletConnect]);
+
+  // Start connection when modal opens
+  useEffect(() => {
+    if (isOpen) {
+      startConnection();
+    }
+
+    return () => {
+      setQrDataUrl('');
+      setConnectionState('generating');
+    };
+  }, [isOpen, startConnection]);
+
+  // Listen for successful connection
+  useEffect(() => {
+    const handleConnected = () => {
+      setConnectionState('connected');
+      // Auto-close after brief success display
+      setTimeout(() => onClose(), 1500);
+    };
+
+    window.addEventListener('walletconnect_connected', handleConnected);
+    return () => window.removeEventListener('walletconnect_connected', handleConnected);
+  }, [onClose]);
+
+  return (
+    <Dialog open={isOpen} onOpenChange={onClose}>
+      <DialogContent className="sm:max-w-md">
+        <DialogHeader>
+          <DialogTitle className="flex items-center gap-2">
+            <Smartphone className="h-5 w-5 text-purple-400" />
+            WalletConnect
+          </DialogTitle>
+          <DialogDescription>
+            {t('walletModal.wcScanQR', 'Scan with pezWallet to connect')}
+          </DialogDescription>
+        </DialogHeader>
+
+        <div className="flex flex-col items-center gap-4 py-4">
+          {/* Generating state */}
+          {connectionState === 'generating' && (
+            <div className="flex flex-col items-center gap-3 py-8">
+              <Loader2 className="h-8 w-8 animate-spin text-purple-400" />
+              <p className="text-sm text-gray-400">
+                {t('walletModal.wcGenerating', 'Generating QR code...')}
+              </p>
+            </div>
+          )}
+
+          {/* QR Code display - waiting for scan */}
+          {connectionState === 'waiting' && qrDataUrl && (
+            <>
+              <div className="bg-white rounded-xl p-3">
+                <img
+                  src={qrDataUrl}
+                  alt="WalletConnect QR Code"
+                  className="w-[280px] h-[280px]"
+                />
+              </div>
+              <div className="flex items-center gap-2 text-sm text-gray-400">
+                <Loader2 className="h-4 w-4 animate-spin" />
+                {t('walletModal.wcWaiting', 'Waiting for wallet to connect...')}
+              </div>
+              <p className="text-xs text-gray-500 text-center max-w-[280px]">
+                {t('walletModal.wcInstructions', 'Open pezWallet app → Settings → WalletConnect → Scan QR code')}
+              </p>
+            </>
+          )}
+
+          {/* Connected state */}
+          {connectionState === 'connected' && (
+            <div className="flex flex-col items-center gap-3 py-8">
+              <CheckCircle className="h-12 w-12 text-green-500" />
+              <p className="text-lg font-medium text-green-400">
+                {t('walletModal.wcConnected', 'Connected!')}
+              </p>
+              {wcPeerName && (
+                <p className="text-sm text-gray-400">{wcPeerName}</p>
+              )}
+              {selectedAccount && (
+                <code className="text-xs text-gray-500 font-mono">
+                  {selectedAccount.address.slice(0, 8)}...{selectedAccount.address.slice(-6)}
+                </code>
+              )}
+            </div>
+          )}
+
+          {/* Error state */}
+          {connectionState === 'error' && (
+            <div className="flex flex-col items-center gap-3 py-8">
+              <XCircle className="h-12 w-12 text-red-500" />
+              <p className="text-sm text-red-400">{errorMsg}</p>
+              <Button
+                onClick={startConnection}
+                variant="outline"
+                className="mt-2"
+              >
+                {t('walletModal.wcRetry', 'Try Again')}
+              </Button>
+            </div>
+          )}
+        </div>
+      </DialogContent>
+    </Dialog>
+  );
+};