Merge origin/main into pr13-revised

Add perception ablation grid (observation channel × fog of war)

Improve Play minimap clarity

Phase 2: Play tab — contextual clicking + per-type unit shapes

Phase 2: Play tab — selection boundary, move arrows, clear selection

Phase 2: fix Start button + tactical minimap (shapes/legend/counts)

Training-parity minimap (real terrain + legend) + viewer (system/thinking/debrief)

Live-smoke fixes: tool-call wire 400, episode resilience, real PNG minimap