feat: crypto-bigint replace Price & Quantity

[kunsonx]

Price & Quantity support u256 size calculation.

[Copilot]

Pull Request Overview

This PR updates the code to support 256‐bit calculations for prices and quantities by replacing u64 with crypto-bigint’s U256. The key changes are:

• Converting Price and Quantity types in production code and tests.
• Updating order update calls, assertions, and arithmetic operations to use U256 and U512.
• Adding dependencies (num-bigint and crypto-bigint) to support big integer arithmetic.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
apex-core/tests/modify.rs	Updated order update calls to wrap numeric literals with Price::from.
apex-core/tests/market_orders.rs	Adjusted test values to compare using Quantity::from for market order slippage and quantity.
apex-core/tests/limit_orders.rs	Updated assertions to use Quantity::from for remaining unit checks.
apex-core/tests/common.rs	Modified order creation helpers to convert raw values via Price::from and Quantity::from.
apex-core/src/engine/types.rs	Changed Price and Quantity types to U256 and revised slippage calculation using U512.
apex-core/src/engine/engine.rs	Updated arithmetic and zero checks to work with U256 methods.
apex-core/benches/common.rs	Updated benchmark helpers for order creation reflecting the new type conversion.
apex-core/Cargo.toml	Added dependencies for num-bigint and crypto-bigint.

Comments suppressed due to low confidence (2)

apex-core/src/engine/types.rs:17

• Consider updating the associated comment for 'Price' to indicate that it is now a 256-bit unsigned integer rather than a 64-bit value, to clarify its purpose in big integer calculations.

pub type Price = U256;

apex-core/src/engine/types.rs:21

• Update the comment for 'Quantity' to reflect that it is now a 256-bit unsigned integer, ensuring consistency with the new arithmetic size and clarifying its usage.

pub type Quantity = U256;

[Copilot]

Pull Request Overview

This PR updates the codebase so that Price and Quantity calculations now use 256‐bit integers via the crypto‑bigint library, enabling support for u256 size arithmetic.

• Refactored order creation functions and tests to use Price::from and Quantity::from conversions instead of direct integer types.
• Updated arithmetic and zero‑checks in engine logic to work with U256, and renamed the slippage tolerance constant for clarity.
• Added necessary dependency updates in Cargo.toml.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
apex-core/tests/modify.rs	Updated update_order calls to convert primitive prices into U256 values.
apex-core/tests/market_orders.rs	Adjusted slippage tolerance and quantity assertions to use the U256 conversion.
apex-core/tests/limit_orders.rs	Updated assertions in tuple comparisons to use Quantity::from conversions.
apex-core/tests/common.rs	Modified helpers for order creation to accept u64 and convert to U256 for price and quantity.
apex-core/src/engine/types.rs	Changed Price and Quantity types to U256 and updated related arithmetic and constant naming.
apex-core/src/engine/engine.rs	Updated arithmetic operations and zero‑checks to handle U256 values in order processing logic.
apex-core/benches/common.rs	Updated benchmark helpers to use U256 conversion in order creation.
apex-core/Cargo.toml	Added crypto‑bigint and num‑bigint dependencies for big integer support.