International merchandise trade remains heavily constrained by fragmented paper-based documentation, disparate data formats and cross-jurisdictional legal friction. While National Single Window (NSW) systems (such as Indian Customs' (ICEGATE) optimize domestic customs clearance, cross-border digital data exchange faces persistent bottlenecks in semantic interoperability, mutual recognition, automated risk interpretability under macroeconomic volatility and the legal singularity of electronic documents of title. This paper establishes an integrated Technical and Legal Framework for Cross-Border Paperless Trade, synthesizing a four-tier architecture—combining UN/CEFACT Reference Data Models, W3C Decentralized Identifiers (DIDs), Verifiable Credentials (VCs) and distributed ledger state anchors—with the legal doctrines of the UNCITRAL Model Law on Electronic Transferable Records (MLETR). Methodologically, this study implements a reproducible, intercontinental testbed linking nodes across India (ap-south-1) and Singapore (ap-southeast-1) to evaluate automated customs risk targeting across four parameterised distribution-shift environments (E_1 Covariate/FX shift, E_2 Logistical Congestion shift, E_3 Concept/Misclassification shift and E_4 Compound shock). We formulate and benchmark StableSHAP and optimal-transport-weighted Weighted StableSHAP (γ∈[0.1,5.0], λ∈[0.1,1.0]) across N=50 random seeds with 95% bootstrap confidence intervals. Statistical evaluations confirm that while Weighted StableSHAP achieves superior feature ranking preservation ("ASI"=0.951±0.010, p=1.4×10^(-7)), standard KernelSHAP remains competitive by minimizing raw attribution deviation ("MASD"=0.084±0.006). The framework is validated via empirical operational telemetry from the G20-backed India–Singapore TradeTrust Live Deployment, demonstrating a 100% elimination of physical document transit delays and a reduction in end-to-end electronic Bill of Lading (e-BL) title transfer times to under two hours. Finally, the paper provides a jurisprudential analysis under modernized Indian statutes—including the Bills of Lading Act, 2025, Carriage of Goods by Sea Act, 2025 (COGSA 2025), Information Technology Act, 2000 and Customs Act, 1962. Grounded in the Supreme Court precedent of Arjun Panditrao Khotkar v. Kailash K. Gorantyal, the study delineates the evidentiary duality under the Bharatiya Sakshya Adhiniyam, 2023 (BSA), establishing that native distributed ledger states constitute self-authenticating Primary Electronic Evidence under Section 62, while local browser outputs operate as Secondary Electronic Evidence governed by automated Section 63(4) compliance certificates.