feat: 添加多链支持和 Lending 借贷系统

- 新增 ARB Sepolia + BNB Testnet 多链支持
- 添加 LendingPanel 借贷系统组件
- 添加 LendingAdminPanel 管理面板
- 添加 USDCPanel USDC 操作组件
- 添加 HoldersPanel 持有人信息组件
- 添加 AutoTestPanel 自动化测试组件
- 重构 LP 组件为模块化结构 (LP/)
- 添加多个调试和测试脚本
- 修复 USDC 精度动态配置
- 优化合约配置支持多链切换

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/scripts/single-buy-test.ts

@@ -0,0 +1,118 @@
+/**
+ * 单账户买入测试脚本
+ * 使用主账户直接执行买入，不需要分发 ETH
+ */
+
+import {
+  createPublicClient,
+  createWalletClient,
+  http,
+  parseUnits,
+  formatUnits,
+  type Address,
+  type Hex
+} from 'viem'
+import { arbitrumSepolia } from 'viem/chains'
+import { privateKeyToAccount } from 'viem/accounts'
+
+const CONTRACTS = {
+  WUSD: '0x6d2bf81a631dFE19B2f348aE92cF6Ef41ca2DF98' as Address,
+  VAULT_YT_A: '0x0cA35994F033685E7a57ef9bc5d00dd3cf927330' as Address,
+}
+
+const MAIN_PRIVATE_KEY = '0xa082a7037105ebd606bee80906687e400d89899bbb6ba0273a61528c2f5fab89' as Hex
+
+const WUSD_ABI = [
+  { inputs: [{ name: 'spender', type: 'address' }, { name: 'amount', type: 'uint256' }], name: 'approve', outputs: [{ type: 'bool' }], stateMutability: 'nonpayable', type: 'function' },
+  { inputs: [{ name: 'account', type: 'address' }], name: 'balanceOf', outputs: [{ type: 'uint256' }], stateMutability: 'view', type: 'function' },
+] as const
+
+const VAULT_ABI = [
+  { inputs: [{ name: '_wusdAmount', type: 'uint256' }], name: 'depositYT', outputs: [], stateMutability: 'nonpayable', type: 'function' },
+  { inputs: [{ name: '_wusdAmount', type: 'uint256' }], name: 'previewBuy', outputs: [{ type: 'uint256' }], stateMutability: 'view', type: 'function' },
+  { inputs: [{ name: 'account', type: 'address' }], name: 'balanceOf', outputs: [{ type: 'uint256' }], stateMutability: 'view', type: 'function' },
+  { inputs: [], name: 'symbol', outputs: [{ type: 'string' }], stateMutability: 'view', type: 'function' },
+] as const
+
+async function main() {
+  console.log('🚀 单账户买入测试\n')
+
+  const publicClient = createPublicClient({
+    chain: arbitrumSepolia,
+    transport: http('https://sepolia-rollup.arbitrum.io/rpc'),
+  })
+
+  const account = privateKeyToAccount(MAIN_PRIVATE_KEY)
+  const walletClient = createWalletClient({
+    account,
+    chain: arbitrumSepolia,
+    transport: http('https://sepolia-rollup.arbitrum.io/rpc'),
+  })
+
+  console.log(`📍 账户: ${account.address}`)
+
+  // 检查余额
+  const ethBalance = await publicClient.getBalance({ address: account.address })
+  const wusdBalance = await publicClient.readContract({
+    address: CONTRACTS.WUSD,
+    abi: WUSD_ABI,
+    functionName: 'balanceOf',
+    args: [account.address],
+  })
+
+  console.log(`⛽ ETH 余额: ${formatUnits(ethBalance, 18)} ETH`)
+  console.log(`💰 WUSD 余额: ${formatUnits(wusdBalance, 18)} WUSD`)
+
+  // 获取金库 symbol
+  const vaultSymbol = await publicClient.readContract({
+    address: CONTRACTS.VAULT_YT_A,
+    abi: VAULT_ABI,
+    functionName: 'symbol',
+  })
+  console.log(`🏦 目标金库: ${vaultSymbol}`)
+
+  // 买入金额
+  const buyAmount = parseUnits('50', 18) // 50 WUSD
+  console.log(`\n📝 买入金额: ${formatUnits(buyAmount, 18)} WUSD`)
+
+  // 预览
+  const previewYT = await publicClient.readContract({
+    address: CONTRACTS.VAULT_YT_A,
+    abi: VAULT_ABI,
+    functionName: 'previewBuy',
+    args: [buyAmount],
+  })
+  console.log(`📊 预计获得: ${formatUnits(previewYT, 18)} ${vaultSymbol}`)
+
+  // 执行买入
+  console.log('\n1️⃣  授权 WUSD...')
+  const approveHash = await walletClient.writeContract({
+    address: CONTRACTS.WUSD,
+    abi: WUSD_ABI,
+    functionName: 'approve',
+    args: [CONTRACTS.VAULT_YT_A, buyAmount],
+  })
+  await publicClient.waitForTransactionReceipt({ hash: approveHash })
+  console.log(`   ✓ 授权成功: ${approveHash}`)
+
+  console.log('\n2️⃣  执行买入...')
+  const buyHash = await walletClient.writeContract({
+    address: CONTRACTS.VAULT_YT_A,
+    abi: VAULT_ABI,
+    functionName: 'depositYT',
+    args: [buyAmount],
+  })
+  await publicClient.waitForTransactionReceipt({ hash: buyHash })
+  console.log(`   ✓ 买入成功: ${buyHash}`)
+
+  // 检查结果
+  const ytBalance = await publicClient.readContract({
+    address: CONTRACTS.VAULT_YT_A,
+    abi: VAULT_ABI,
+    functionName: 'balanceOf',
+    args: [account.address],
+  })
+  console.log(`\n✅ ${vaultSymbol} 余额: ${formatUnits(ytBalance, 18)}`)
+}
+
+main().catch(console.error)