feat(hyperliquid): Auto-generate wallet address from private key

Enable automatic wallet address generation from private key for Hyperliquid
exchange, simplifying user onboarding and reducing configuration errors.
Backend Changes (trader/hyperliquid_trader.go):
- Import crypto/ecdsa package for ECDSA public key operations
- Enable wallet address auto-generation when walletAddr is empty
- Use crypto.PubkeyToAddress() to derive address from private key
- Add logging for both auto-generated and manually provided addresses
Frontend Changes (web/src/components/AITradersPage.tsx):
- Remove wallet address required validation (only private key required)
- Update button disabled state to only check private key
- Add "Optional" label to wallet address field
- Add dynamic placeholder with bilingual hint
- Show context-aware helper text based on input state
- Remove HTML required attribute from input field
Translation Updates (web/src/i18n/translations.ts):
- Add 'optional' translation (EN: "Optional", ZH: "可选")
- Add 'hyperliquidWalletAddressAutoGenerate' translation
  EN: "Leave blank to automatically generate wallet address from private key"
  ZH: "留空将自动从私钥生成钱包地址"
Benefits:
✅ Simplified UX - Users only need to provide private key
✅ Error prevention - Auto-generated address always matches private key
✅ Backward compatible - Manual address input still supported
✅ Better UX - Clear visual indicators for optional fields
Technical Details:
- Uses Ethereum standard ECDSA public key to address conversion
- Implementation was already present but commented out (lines 37-43)
- No database schema changes required (hyperliquid_wallet_addr already nullable)
- Fallback behavior: manual input > auto-generation
Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/i18n/translations.ts

@@ -194,6 +194,8 @@ export const translations = {
     enterPassphrase: 'Enter Passphrase (Required for OKX)',
     hyperliquidPrivateKeyDesc: 'Hyperliquid uses private key for trading authentication',
     hyperliquidWalletAddressDesc: 'Wallet address corresponding to the private key',
+    hyperliquidWalletAddressAutoGenerate: 'Leave blank to automatically generate wallet address from private key',
+    optional: 'Optional',
     testnetDescription: 'Enable to connect to exchange test environment for simulated trading',
     securityWarning: 'Security Warning',
     saveConfiguration: 'Save Configuration',
@@ -608,6 +610,8 @@ export const translations = {
     enterPassphrase: '输入Passphrase (OKX必填)',
     hyperliquidPrivateKeyDesc: 'Hyperliquid 使用私钥进行交易认证',
     hyperliquidWalletAddressDesc: '与私钥对应的钱包地址',
+    hyperliquidWalletAddressAutoGenerate: '留空将自动从私钥生成钱包地址',
+    optional: '可选',
     testnetDescription: '启用后将连接到交易所测试环境，用于模拟交易',
     securityWarning: '安全提示',
     saveConfiguration: '保存配置',