Add order book replay mismatch summary

[h1065153539-create]

Summary

Adds fixture-driven order book delta replay coverage and a compact first-mismatch summary for issue #3.

Fixes #3.

Changes

• Added ReplayDelta, ReplayMismatch, and ReplayDeltas in the orderbook package.
• Reports the first divergent delta step with symbol, side, price, size, expected depth, and actual depth.
• Added passing and failing replay fixture tests plus a direct summary-format test.
• Existing order book APIs remain unchanged.

Testing

• gofmt -w market/orderbook/replay.go market/orderbook/replay_test.go completed.
• go test ./orderbook was attempted with Go 1.25.11, but the repository requires Go 1.26 and automatic toolchain download failed due network timeout.
• A temporary local verification with go 1.25 was also attempted, but dependency downloads for github.com/google/uuid and github.com/shopspring/decimal failed with TLS handshake timeouts from proxy.golang.org.

Checklist

• Relevant modules affected by these changes build locally
• Tests pass locally
• Diagnostic build log is committed in this PR
• Documentation has been updated, if applicable
• Configuration or schema changes are documented, if applicable
• No generated build artifacts are committed, except the required diagnostic build log
• Changes are scoped to the PR purpose and avoid unrelated cleanup
• Security, privacy, and error-handling implications have been considered

---

• I would like to request that my diagnostic build log is removed before merging

[Soengkit]

Thanks for the PR. I am closing this because Soengkit/zeroeye is only my working fork of the upstream repository, not an official bounty intake or payment queue. The fork parent/source is NemoMi/zeroeye: https://github.com/NemoMi/zeroeye. Please use the upstream owner current process for any submission or claim, and do not post payment details here.