docs: update failover-provider beta.2 and lending-aave-evm beta.4 docs

Created by: ihsraham

Summary

• update lending-aave-evm docs for v1.0.0-beta.4
• add April 19, 2026 changelog coverage for failover-provider v1.0.0-beta.2 and lending-aave-evm v1.0.0-beta.4

Documentation Fixes

• document the widened per-operation ERC-4337 override surface for @tetherto/wdk-protocol-lending-aave-evm, covering paymaster-token, sponsorship-policy, and native-coin gas modes
• update the Aave examples to use the current paymasterToken: { address } shape from @tetherto/wdk-wallet-evm-erc-4337

Changelog Updates

• failover-provider v1.0.0-beta.2: remove unnecessary published type definitions without changing runtime failover behavior
• lending-aave-evm v1.0.0-beta.4: expand per-operation ERC-4337 config overrides from paymasterToken-only to the wallet module's paymaster-token, sponsorship-policy, and native-coin gas modes

Release References

• wdk-failover-provider release PR: #10
• wdk-protocol-lending-aave-evm release PR: #11

Excluded From Docs

• failover-provider v1.0.0-beta.2 did not require page-level docs edits after comparing the published beta.1 and beta.2 surfaces, so it is changelog-only in this PR