feat(frontend): align wUSDT Asset ID with SDK (1000)

This commit aligns the frontend wUSDT implementation with the SDK runtime
constants, ensuring consistency across the entire stack.

Changes:
- Update ASSET_IDS.WUSDT from 2 → 1000 (matches SDK constants)
- Add ASSET_CONFIGS with wUSDT configuration (6 decimals, min balance)
- Update all asset queries in AccountBalance.tsx to use ASSET_IDS.WUSDT
- Update pool queries for wHEZ/wUSDT and PEZ/wUSDT pools
- Update USDTBridge.tsx burn transaction to use ASSET_IDS.WUSDT
- Refactor usdt.ts to reference ASSET_CONFIGS instead of hardcoded values

Asset ID Allocation Strategy:
- 0-999: Reserved for protocol tokens (wHEZ, PEZ, etc.)
- 1000+: Bridged/wrapped external assets (wUSDT, etc.)

Technical Details:
- wUSDT uses 6 decimals (USDT standard), not 12 like native HEZ
- All frontend code now uses centralized ASSET_CONFIGS
- ESLint passes with 0 errors (8 pre-existing warnings unrelated to changes)

This is part of Phase 1 wUSDT infrastructure setup, working in parallel
with SDK benchmarking builds currently running in background.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

shared/lib/usdt.ts

@@ -4,15 +4,15 @@
 // Handles wUSDT minting, burning, and reserve management
 
 import type { ApiPromise } from '@polkadot/api';
-import { ASSET_IDS } from './wallet';
+import { ASSET_IDS, ASSET_CONFIGS } from './wallet';
 import { getMultisigMembers, createMultisigTx } from './multisig';
 
 // ========================================
 // CONSTANTS
 // ========================================
 
-export const WUSDT_ASSET_ID = ASSET_IDS.WUSDT;
-export const WUSDT_DECIMALS = 6; // USDT has 6 decimals
+export const WUSDT_ASSET_ID = ASSET_CONFIGS.WUSDT.id;
+export const WUSDT_DECIMALS = ASSET_CONFIGS.WUSDT.decimals;
 
 // Withdrawal limits and timeouts
 export const WITHDRAWAL_LIMITS = {