refactor(scenario): delete predator_evade; template is the canonical scenario

refactor(scenario): rename pack_evade -> template

feat(web): unify memory replay onto the single play board

fix(memory): legacy replay block sizes match resized pack_evade (3x3 predator, 2x2 focal)

feat(web): multi-agent memory replay caption + colour legend

refactor: restructure proteus into game/web subpackages

feat(web): policy memory modes + replay-only panel (drop text) + graceful provider errors

feat(web): step-through memory replay grid in the memory panel

feat(web): ship per-turn replay frames in the memory payload

feat(web): show the handover memory block in the UI at the start (expandable panel)

feat(web): selectable handover memory (default/none/persona/generate/latest) + action quota 100