Accept any TxSigner in PerpClient; add aws feature for KMS signing

[Praz314159]

PerpClient::new/new_arbitrum/new_arbitrum_sepolia are now generic over S: TxSigner + Send + Sync + 'static instead of requiring a concrete PrivateKeySigner. Signing already flowed through EthereumWallet asynchronously, so remote signers drop in with no pipeline changes, and existing PrivateKeySigner callers compile unchanged.

New opt-in aws cargo feature enables alloy/signer-aws, and examples/aws_kms_signer.rs shows the end-to-end flow: AWS credential chain -> KMS client -> AwsSigner -> PerpClient. This lets bots sign with a KMS asymmetric secp256k1 key that never leaves AWS, gated by IAM.

Summary by CodeRabbit

• New Features

  • Added AWS KMS signing support behind an optional feature flag.
  • Added a new example showing how to sign and send transactions using a remote AWS KMS key.

• Bug Fixes

  • Client setup now works with more signer types, including remote signers, instead of only local private keys.

• Documentation

  • Updated release notes and crate docs to reflect the broader signer support and the new AWS KMS workflow.

[coderabbitai]

📝 Walkthrough

Walkthrough

PerpClient constructor methods (new, new_arbitrum, new_arbitrum_sepolia) are generalized to accept any signer implementing TxSigner<Signature> + Send + Sync + 'static instead of only PrivateKeySigner. An aws Cargo feature, AWS KMS dev-dependencies, and a new aws_kms_signer example are added, along with documentation and changelog updates.

Changes

Generic Signer Support and AWS KMS Example

Layer / File(s)	Summary
Generalize PerpClient constructors src/client/mod.rs	PerpClient::new, new_arbitrum, and new_arbitrum_sepolia accept a generic S: TxSigner<Signature> + Send + Sync + 'static instead of PrivateKeySigner, deriving the address via TxSigner::address and updating imports/docs.
aws feature and KMS dependencies Cargo.toml	Adds an aws feature enabling alloy/signer-aws, aws-config/aws-sdk-kms dev-dependencies, and a new aws_kms_signer example gated behind the aws feature.
AWS KMS signer example examples/aws_kms_signer.rs	New example demonstrates creating an AwsSigner from KMS, connecting via PerpClient::new_arbitrum_sepolia, syncing client state, and opening/closing a taker position.
Documentation and changelog src/lib.rs, CHANGELOG.md	Crate docs and changelog updated to describe generic TxSigner support and the new AWS KMS feature/example.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Example as aws_kms_signer.rs
  participant KmsClient as aws_sdk_kms::Client
  participant AwsSigner
  participant PerpClient
  participant Chain as Arbitrum Sepolia

  Example->>KmsClient: create client from AWS config
  Example->>AwsSigner: create with KMS key id
  Example->>PerpClient: new_arbitrum_sepolia(transport, AwsSigner, deployments)
  PerpClient->>Chain: sync_nonce, refresh_gas, ensure_approval
  Example->>PerpClient: open_taker(...)
  PerpClient->>AwsSigner: sign transaction via KMS
  PerpClient->>Chain: submit tx
  Example->>PerpClient: adjust_taker(...) to close position
  PerpClient->>AwsSigner: sign transaction via KMS
  PerpClient->>Chain: submit tx

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🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the two main changes: generic TxSigner support in PerpClient and the new AWS KMS signing feature.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/generic-signer-kms

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[coderabbitai]

🧹 Nitpick comments (1)

examples/aws_kms_signer.rs (1)

73-97: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Example uses no slippage bounds (amt1_limit: 0 / u128::MAX).

For a demo this is fine, but since this example is likely to be copy-pasted into real bots, consider a brief comment noting these are placeholder values and production code should set real slippage limits.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@examples/aws_kms_signer.rs` around lines 73 - 97, The example in
aws_kms_signer.rs uses placeholder slippage bounds in open_taker and
adjust_taker, which can be misleading if copied into production code. Add a
brief inline comment near the OpenTakerParams and AdjustTakerParams setup
explaining that amt1_limit values like 0 and u128::MAX are demo placeholders,
and that real bots should set explicit slippage limits before using
client.open_taker and client.adjust_taker.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@examples/aws_kms_signer.rs`:
- Around line 73-97: The example in aws_kms_signer.rs uses placeholder slippage
bounds in open_taker and adjust_taker, which can be misleading if copied into
production code. Add a brief inline comment near the OpenTakerParams and
AdjustTakerParams setup explaining that amt1_limit values like 0 and u128::MAX
are demo placeholders, and that real bots should set explicit slippage limits
before using client.open_taker and client.adjust_taker.

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ℹ️ Review info

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Run ID: df1d0297-2246-496e-8766-8c440dab7b5e

📥 Commits

Reviewing files that changed from the base of the PR and between 6f74cbc and 9e35094.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (5)

• CHANGELOG.md
• Cargo.toml
• examples/aws_kms_signer.rs
• src/client/mod.rs
• src/lib.rs