Self-contained fresh-session prompt that points at the BSP-port
shipped-handoff, summarizes the foundation work to keep vs delete,
notes the retail decomp anchors for CTransition::transitional_insert /
last_known_contact_plane, and includes the session-lesson reminder:
probe-first, design-second.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>