Upgrade viem and add new chains

[johnpmitsch]

Note

Upgrade viem to ^2.38, add mappings for many new chains, refresh test recordings, and make Polly recording configurable via env var, with minor docs tweaks.

• SDK/Core:
  • Upgrade viem to ^2.38.6 and align dependencies.
  • Expand chains.ts mapping to support many networks (e.g., Arbitrum Sepolia/Nova, Base(+Sepolia), Blast(+Sepolia), Cyber(+Testnet), Mantle(+Sepolia), Scroll(+Sepolia), Polygon Amoy, Sei(+Devnet), 0G, Abstract(+Testnet), B3(+Sepolia), Flare(+Coston2), Gravity Alpha, Hemi(+Sepolia), Hyperliquid EVM Testnet, Immutable zkEVM(+Testnet), Ink(+Sepolia), JOC Mainnet, Kaia(+Kairos), Linea, Monad Testnet, Morph, Nomina, Peaq, Plasma(+Testnet), Soneium, Sonic, Story(+Aeneid), Unichain(+Sepolia), Vana(+Moksha), World Chain(+Sepolia), Xai(+Testnet), X Layer).
  • Fix chain name expectation to BNB Smart Chain Testnet.
• Tests/Recordings:
  • Add/update extensive Polly .har recordings for core and Solana tests.
  • Remove per-test recordIfMissing flags; withPolly now honors POLLY_RECORD_IF_MISSING env var.
• Docs:
  • Minor README clarifications for SDK description and test re-record instructions.

^{Written by Cursor Bugbot for commit fac6b4c. This will update automatically on new commits. Configure here.}

[coveralls]

coverage: 86.385%. remained the same
when pulling fac6b4c on dx-4220-sdk-upgrade-viem-and-add-new-chains
into 9b0696e on main.