feat: add peaq EVM support (chainId 3338)

[lavish0000]

Following the pattern in #204 and #157:

• Add peaq to EVM networks with chainId: 3338
• Configure USDC on peaq: 0xbbA60da06c2c5424f03f7434542280FCAd453d10
• Import peaq directly from viem/chains and extend wallet.ts switch
• Update network mappings and supported networks list

This enables x402 payments on peaq network using the existing EIP-3009 exact scheme with lower gas costs and faster settlement times.

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[vercel]

@lavish0000 is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.

[apmcdermott]

@lavish0000 LGTM. Need you to sign your commits before this can be merged in though.

[lavish0000]

Thanks a lot @apmcdermott 🙂. I have signed the commit. Let me know if anything else is needed from my side

[lavish0000]

Hey @apmcdermott 🙂, anything else you need from us to get this merged? Please let me know