feat: add AetheriumX voucher token metadata and icons

[AetheriumX-DCIP]

Summary

Adds metadata and pure-vector SVG icons for four AetheriumX Voucher Vault ERC-20 receipt tokens across Ethereum and BNB Smart Chain.

Assets

Network	Symbol	Metadata name	Contract
Ethereum (eip155:1)	xEthWETH	AetheriumX Ethereum WETH	0x01AB7aa98213Cd1E18D9405F039c554266A82847
BNB Smart Chain (eip155:56)	xBnbWBNB	xBnbWBNB	0x01AB7aa98213Cd1E18D9405F039c554266A82847
BNB Smart Chain (eip155:56)	xBnbUSDT	AetheriumX BNB Smart Chain USD	0xb1F77C4536603CBEaA2cB5D0d7dEE9cA1022d21F
BNB Smart Chain (eip155:56)	xBnbBTCB	AetheriumX BTCB	0x23ec765c63e0C1Dd2204734F58e1F8610C61D1FE

All four tokens use 18 decimals. The identical xEthWETH/xBnbWBNB hexadecimal address is intentionally separated by its CAIP-19 chain namespace. The xBnbWBNB metadata name follows the current block-explorer token name.

These are protocol voucher/receipt tokens representing supported staking positions; they are not the underlying WETH, WBNB, USDT, or BTCB assets themselves. xBnbWBNB represents users' BNB staking positions, with WBNB serving as the wrapped/settlement asset reference in the workflow and symbol.

Icon validation

• Pure vector SVG only
• No embedded raster <image> elements
• No <style>, <foreignObject>, nested SVG, filters, fonts, or external resources
• Full square background with safe padding for circular wallet crops

Official verification

AetheriumX confirms that its official Voucher Vault pages display the current chain-qualified contracts used in this PR:

• xEthWETH: https://axt.fun/voucher-vault/xethweth/
• xBnbWBNB: https://axt.fun/voucher-vault/xbnbwbnb/
• xBnbUSDT: https://axt.fun/voucher-vault/xbnbusdt/
• xBnbBTCB: https://axt.fun/voucher-vault/xbnbbtcb/

Address-specific explorer references

• Ethereum xEthWETH: https://etherscan.io/token/0x01AB7aa98213Cd1E18D9405F039c554266A82847
• BNB Smart Chain xBnbWBNB: https://bscscan.com/token/0x01AB7aa98213Cd1E18D9405F039c554266A82847
• BNB Smart Chain xBnbUSDT: https://bscscan.com/token/0xb1F77C4536603CBEaA2cB5D0d7dEE9cA1022d21F
• BNB Smart Chain xBnbBTCB: https://bscscan.com/token/0x23ec765c63e0C1Dd2204734F58e1F8610C61D1FE

Project references

• Official website: https://axt.fun/
• Voucher Vault: https://axt.fun/voucher-vault/
• Whitepaper: https://axt.fun/doc/AetheriumX-White%20Paper.pdf
• Security audit profile (implementation audit reference): https://skynet.certik.com/projects/aetheriumx
• Contact: office@axt.fun

The block explorers and official Voucher Vault pages above are the address-specific references for the contracts in this PR. The CertiK link is provided as a security-audit reference for the contract implementation.

[AetheriumX-DCIP]

Official verification update from AetheriumX:

The official Voucher Vault pages have been updated to the current chain-qualified contracts used in this PR:

• xEthWETH (Ethereum): https://axt.fun/voucher-vault/xethweth/
• xBnbWBNB (BNB Smart Chain): https://axt.fun/voucher-vault/xbnbwbnb/
• xBnbUSDT (BNB Smart Chain): https://axt.fun/voucher-vault/xbnbusdt/
• xBnbBTCB (BNB Smart Chain): https://axt.fun/voucher-vault/xbnbbtcb/

xBnbWBNB represents users' BNB staking positions; WBNB is the wrapped/settlement asset reference used by the voucher workflow and symbol. The submission is ready for review.

[AetheriumX-DCIP]

Metadata verification update:

• The BNB Smart Chain token metadata name has been aligned with the current block-explorer token name: xBnbWBNB.
• symbol remains xBnbWBNB and decimals remains 18.
• Address-specific explorer references have been added to the PR description.
• The CertiK link is identified as a contract-implementation audit reference; the official Voucher Vault pages and block explorers are the address-specific references for this submission.