Implement wire protocol feature for binary order entry

[joaquinbejar]

Overview

Implement a binary wire protocol feature for order entry (NewOrder, Cancel, CancelReplace, MassCancel) with execution report and market-data (trade, book-update) responses. Protocol is little-endian framed binary (length:u32 | kind:u8 | payload), not serde-JSON. Target for integration with a gateway / networking layer.

Context

• Files: new src/wire/ submodule or feature-gated src/orderbook/wire.rs
• Worktest requirement: "binary wire protocol... real binary protocol you defined, not serde-JSON over HTTP"
• Integration point: examples/wire_server.rs listening on TCP localhost:9999
• Non-functional: integer prices/qty only, no floats; explicit schema, no implicit type coercion

Acceptance criteria

• cargo clippy --all-targets --all-features -- -D warnings clean
• cargo fmt --all --check clean
• cargo test --all-features clean
• cargo build --release --all-features clean
• Wire protocol documented in doc/wire.md with example hex dumps
• Round-trip test: 10+ message types encode/decode identically
• Unit test: test_wire_neworder_malformed rejects invalid bytes cleanly
• Example: cargo run --example wire_client --all-features connects, submits order, receives exec report
• No panics on invalid wire input; all errors returned as rejection codes

[joaquinbejar]

Duplicate of #59, tracked there.

[joaquinbejar]

Duplicate of #59 — implemented by PR #83. Closing as not planned.