Modern enterprise retail platforms operate as complex omnichannel ecosystems integrating Point-of-Sale (POS) systems, e-commerce platforms, mobile applications, self-checkout systems, and backend settlement services. While individual channel components are typically validated in isolation, cross-channel transaction integrity — defined as the correctness, consistency, and completeness of transaction state across multiple channel boundaries — remains a largely unaddressed governance challenge in enterprise software quality engineering. This paper introduces the Cross-Channel Transaction Integrity Framework (CCTIF), a four-layer governance architecture designed to detect, prevent, and remediate integrity violations across omnichannel retail systems. The framework formalizes six primary categories of cross-channel integrity failures, including Channel State Divergence, Promotion Consistency Violations, Loyalty Point Reconciliation Errors, Payment Tender Boundary Failures, Inventory Oversell Conditions, and Asynchronous Settlement Discrepancies. CCTIF is structured across four layers: Cross-Channel State Instrumentation (CCSI), Cross-Channel Consistency Validation (CCCV), Integrity Violation Response (IVR), and Continuous Governance and Analytics (CGA). These layers collectively enable real-time transaction state monitoring, cross-channel consistency validation, automated remediation, and governance-driven analytics. Observational analysis across enterprise retail deployments demonstrates that unstructured validation approaches result in cross-channel integrity failure rates ranging from 12% to 18% under peak conditions. Application of CCTIF was associated with observed failure rate reductions of approximately 84%, reconciliation accuracy improvements exceeding 90%, and significant reductions in dispute resolution time. These findings highlight the importance of treating transaction integrity as an emergent system property requiring explicit governance mechanisms rather than isolated per-channel validation. This work contributes a structured governance model for managing transaction correctness in high-volume distributed retail environments and provides a foundation for future research in cross-channel validation, distributed system correctness, and AI-driven quality engineering.