feat: add bulk public account reads

[3esmit]

🎯 Purpose

Add bulk public-account reads across the sequencer RPC, wallet core, and wallet FFI.

Wallet consumers can now retrieve multiple full account states in one network request and one sequencer state-lock acquisition, instead of issuing one request per account.

Closes #617.

⚙️ Approach

• Add ordered getAccounts(Vec<AccountId>) -> Vec<Account> sequencer RPC.
• Preserve existing account lookup semantics, input order, and duplicate IDs.
• Support empty, single-account, and multi-account requests.
• Add WalletCore::get_accounts_public.
• Add FFI bulk-read and matching memory-release functions.
• Expose the FFI batch limit and an explicit invalid-argument error.
• Limit batches to 24 accounts so worst-case JSON responses remain below the default 10 MiB transport limit.
• Regenerate the C header and add unit and integration coverage.

🧪 How to Test

cargo test -p sequencer_service_rpc --features client,server --lib
cargo test -p wallet-ffi --lib

cargo test -p integration_tests \
  --test account \
  get_public_accounts_returns_states_in_input_order \
  -- --exact

cargo test -p integration_tests \
  --test wallet_ffi \
  test_wallet_ffi_get_accounts_public \
  -- --exact

cargo check -p wallet -p wallet-ffi -p sequencer_service
cargo fmt --all -- --check

The tests cover empty input, ordered multi-account results, duplicate IDs, unknown accounts, oversized requests, null FFI inputs, and nested FFI allocation cleanup.

🔗 Dependencies

None.

🔜 Future Work

Expose the new wallet FFI operation through higher-level execution-zone consumers as needed.

📋 PR Completion Checklist

• Complete PR description
• Implement the core functionality
• Add/update tests
• Add/update documentation and inline comments

[Copilot]

Pull request overview

Adds a bulk public-account read pathway end-to-end (sequencer RPC → wallet core → wallet FFI), enabling consumers to fetch multiple full account states in a single network request while preserving input order and duplicate IDs.

Changes:

• Introduces sequencer RPC method getAccounts(Vec<AccountId>) -> Vec<Account> with a 24-account batch limit.
• Adds WalletCore::get_accounts_public and exposes the operation via wallet FFI, including a matching free function and an explicit invalid-argument error.
• Adds integration and unit coverage for ordering, empty input, duplicate IDs, null/oversized FFI inputs, and nested allocation cleanup.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lez/wallet/src/lib.rs	Adds wallet-core bulk public account read method.
lez/wallet-ffi/wallet_ffi.h	Regenerates header to expose batch read API, free function, error code, and limit constant.
lez/wallet-ffi/src/types.rs	Adds FfiAccountDataList for returning bulk account data over FFI.
lez/wallet-ffi/src/lib.rs	Defines FFI batch limit and compile-time asserts it matches sequencer RPC.
lez/wallet-ffi/src/error.rs	Adds InvalidArgument error code for unsupported argument ranges.
lez/wallet-ffi/src/account.rs	Implements wallet_ffi_get_accounts_public and wallet_ffi_free_accounts_public, plus unit test for nested cleanup.
lez/wallet-ffi/cbindgen.toml	Exports the batch limit constant through cbindgen.
lez/sequencer/service/src/service.rs	Implements server-side get_accounts RPC handler with max-batch enforcement.
lez/sequencer/service/rpc/src/lib.rs	Extends RPC trait with getAccounts and defines MAX_ACCOUNTS_PER_REQUEST (+ size guard test).
lez/sequencer/service/rpc/Cargo.toml	Adds serde_json dev-dependency for RPC response sizing test.
integration_tests/tests/wallet_ffi.rs	Adds integration test coverage for FFI bulk public account reads and error cases.
integration_tests/tests/account.rs	Adds integration test coverage for RPC ordering/duplicates/unknown IDs/oversized batch behavior.
Cargo.lock	Records dependency graph update for new dev-dependency usage.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.