feat(tempo): add stateless charge actions

[deodad]

Summary

Add stateless Tempo charge fill and credential creation actions.

Motivation

mpp_authorize is a proposed wallet RPC that lets JSON RPC accounts route MPP payments to access keys.

Splitting out charge fill and credential creation gives accounts one stable place to inspect Tempo calls for signer selection without reimplementing transfer splits, attribution memos, autoswap, fee-payer handling, or credential formatting.

Changes

• Added src/tempo/Charge.ts with fill and createCredential actions.
• Refactored src/tempo/client/Charge.ts to use the stateless charge actions internally.
• Added localnet coverage in src/tempo/Charge.test.ts for filled calls, pull credentials, proof credentials, and Tempo access-key signing.
• Tightened autoswap call typing to return viem Call[].

Testing

pnpm test src/tempo/Charge.test.ts src/tempo/client/Charge.test.ts

Result: 2 test files passed, 10 tests passed.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/mppx@485

commit: 4612cec