fix: correct wHEZ asset ID from 0 to 2

tokenWrapper pallet on Asset Hub creates wHEZ as Asset ID 2, not 0.

Asset IDs on Asset Hub:
- Asset 1: PEZ
- Asset 2: wHEZ (via tokenWrapper)
- Asset 1000: wUSDT

Updated:
- shared/constants/index.ts: KNOWN_TOKENS
- shared/lib/wallet.ts: ASSET_IDS.WHEZ default
- AccountBalance.tsx: pool queries
- InitializeHezPoolModal.tsx: balance query

web/src/components/dex/InitializeHezPoolModal.tsx

@@ -85,8 +85,8 @@ export const InitializeHezPoolModal: React.FC<InitializeHezPoolModalProps> = ({
         const freeBalance = balance.data.free.toString();
         setHezBalance(freeBalance);
 
-        // wHEZ balance (asset 0 on Asset Hub)
-        const whezData = await assetHubApi.query.assets.account(0, account);
+        // wHEZ balance (asset 2 on Asset Hub - tokenWrapper creates asset 2)
+        const whezData = await assetHubApi.query.assets.account(2, account);
         setWhezBalance(whezData.isSome ? whezData.unwrap().balance.toString() : '0');
       } catch (error) {
         if (import.meta.env.DEV) console.error('Failed to fetch balances from Asset Hub:', error);