Pre-formal Protocol Freeze for K2-B3 Fixed-Route Nav2 Ablation

This archive freezes the prospective K2-B3 fixed-route repeated Nav2 ablation before any formal trial is executed. The formal design evaluates targeted repair, no padding, and no footprint repair variants across two controlled support-defect geometries (B3D03 and B3D04). Clean, defect, and repaired conditions are evaluated with 20 independently reset Nav2 trials per variant-defect-condition cell, for 360 planned formal records. The archive contains the formal protocol, 18-cell execution plan, frozen center-through goal files, SHA-256 index, controlled-defect catalog, world manifests, protocol-generation script, and dedicated Nav2 runner. Earlier K2-B3 open-loop route-robustness records are retained as pilot evidence only. They are not Nav2 formal data and will not be pooled with this formal population. The formal runner requires this exact protocol to be externally published and certified before execution.