[SPR]-calibrated wall oracle catches the maze center passage missing from the render

Three results in one chain. (1) wall_collision calibration now comes from [SPR] telemetry instead of screenshot sprite-hunting: GRP1 drives the score/lives band EVERY frame (grp1_last pins at the band bottom), so window height cannot identify pac — but grp1_first can: it is pac top when drawn and the band fixed top when starved, making the band top the MODE of grp1_first.

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