1\begin{table}[htbp]\centering\footnotesize2\caption{Validation of the cross-merchant matching tiers (60 pairs per tier)}\label{tab:match_val}3\begin{tabular}{lrrrr}\toprule4Tier & Pairs with consensus & Same product & Different & Same product, comparable-variant pairs \\\midrule5A & 56 & 0.92 & 0.02 & 0.90 \\6B & 54 & 0.90 & 0.00 & 0.96 \\7C & 52 & 0.77 & 0.10 & 0.77 \\8D & 48 & 0.17 & 0.60 & 0.19 \\9\bottomrule\end{tabular}10\begin{minipage}{0.95\textwidth}\vspace{2pt}\footnotesize\textit{Notes:} Two independent LLM annotators (agreement 0.88; consensus on 88% of pairs). Tier A = shared merchant SKU; B = same brand and identical normalised title; C = same brand, fuzzy title; D = identical title without brand (never used for inference).\end{minipage}11\end{table}12