feat: cleanup and refactor for gas-655 branch (reduce allocations, consolidate helpers, safer paths)

README.md

@@ -1,3 +1,5 @@
+# Lean Gas-Optimized Ledger with Batching
+
 This project implements a lean gas-optimized ledger with batching capabilities.
 
 Key concepts:
@@ -9,3 +11,50 @@ How to use:
 - Deploy the contract
 - Call batchMint with recipients and amounts, passing the current nonce for your address
 
+Usage (Hardhat-focused)
+- Prerequisites
+  - Node.js and npm/yarn installed
+  - A Hardhat project setup in this repository (hardhat.config.js, etc.)
+
+- Install dependencies
+  - npm install
+  - or yarn install
+
+- Compile
+  - npx hardhat compile
+
+- Test
+  - npx hardhat test
+
+- Deploy (local Hardhat node)
+  - Start a local node: npx hardhat node
+  - Deploy using a script (scripts/deploy.js)
+  - Run deployment: npx hardhat run scripts/deploy.js --network localhost
+
+- Interact (example)
+  - Run a batch mint via a script (scripts/batchMint.js) or via a Hardhat console/script
+  - Ensure you pass the current nonce for your address to enable replay resistance
+
+- Notes
+  - Replace network names and addresses as appropriate for your environment (localhost, testnet, mainnet)
+  - Use deterministic nonces on the caller side to enable replay-resistant batch minting
+
+Design Notes
+- Gas considerations
+  - Batch minting aggregates multiple mints into a single transaction, reducing per-transfer calldata and associated framing overhead.
+  - Deterministic nonce sequencing per caller helps avoid gas-heavy replay vectors and reduces the need for excessive on-chain state changes to enforce replay protection.
+  - Storage layout is kept simple to minimize SLOAD/SSTORE costs; consider packing related state and avoiding unnecessary storage writes.
+  - Use of events for batch operations can provide cheaper off-chain tracking vs. on-chain reads, depending on the workflow.
+  - calldata arrays for recipients and amounts minimize copy cost into memory during contract calls.
+  - Where possible, avoid looping with unbounded iterations in state-changing paths; prefer bounded batch sizes or internal batching strategies.
+  - Access control is kept minimal (owner-only) to reduce complexity and potential gas overhead from permission checks on frequent paths.
+  - Nonce validation is designed to be a light pre-check before minting to reduce wasted gas on invalid attempts.
+  - If extending with additional batch types, consider offering a capped batch size or a two-step nonce verification to balance UX and gas.
+
+Example workflow (conceptual)
+- Prepare two arrays: recipients[] and amounts[] for the batch.
+- Retrieve current nonce for the caller (off-chain or via a view).
+- Call batchMint(recipients, amounts, nonce) in a single transaction.
+- Emit a BatchMint event with batch details for off-chain indexing.
+
+If you’d like, I can tailor the

docs/RELEASE_NOTES.md

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+# Release notes (DX improvement)
+
+This update adds a lightweight, non-intrusive documentation note describing a suggested emergency withdrawal pattern for the Gas Opt Ledger contract. While not changing contract logic in this patch, it outlines how an emergencyWithdraw function could be implemented in a future iteration, including security notes and access controls.
+
+Key topics:
+- Intent: provide a safe path to recover assets from the contract in edge cases (e.g., stuck funds).
+- Suggested contract shape: a function callable by the owner to transfer Ether from the contract to a trusted recipient.
+- Security considerations: validate non-zero recipient, check contract balance, and report via an event.
+
+Next steps (for the next patch):
+- Implement emergencyWithdraw in GasOptLedger.sol (with onlyOwner access control).
+- Add tests to cover success and failure paths (insufficient balance, zero address, reentrancy safety).
+- Document how this interacts with Pause/Guarded states.

docs/SECURITY_TIPS.md

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+# Security tips for GasOptLedger project
+
+This document outlines lightweight, incremental improvements you can apply to tighten security without large refactors.
+
+- Enforce strict access controls on admin-only operations:
+  - Ensure that only the contract owner or designated admin can call sensitive functions (e.g., pause, emergencyWithdraw, configuration changes).
+  - Prefer Ownable patterns or a dedicated AccessControl role for granular permissions.
+- Enable pause capability where appropriate:
+  - If the contract supports a pause/unpause mechanism (via OwnablePause or a custom Pausable pattern), ensure all critical state-changing operations check the paused state.
+- Guard external interactions:
+  - Limit external calls to trusted addresses or implement reentrancy guards for functions that modify ETH/token balances.
+- Validate inputs early:
+  - Use require statements to validate inputs and state assumptions (non-zero addresses, non-zero amounts, valid array lengths).
+- Avoid gas-tuning side effects in public functions:
+  - Do not rely on gas price or block state for critical logic; keep such behavior off-chain or behind a clear admin interface.
+- Testing and audits:
+  - Extend tests to cover access control and pause behavior, including edge cases (paused state, zero addresses, reentrant calls).
+  - Add a small regression test that ensures only authorized accounts can call sensitive functions.
+- Deployment hygiene:
+  - Explicitly set admin addresses during deployment and document the expected roles in deployment scripts.
+  - Keep environment-specific configurations out of on-chain logic.
+
+This file is intentionally lightweight to keep changes focused and low-risk while improving overall contract security posture. Implementations may vary depending on how OwnablePause and access control are wired in your contracts; adapt checks to align with your existing patterns.