PimSim: deployment-site capture and scene cooking

[dimos-bot]

Compile one real deployment site into the same executable scene contract.

Acceptance

• Support PortalCam or a calibrated 360/fisheye-camera-plus-lidar rig
• Retain raw images, lidar, timestamps, calibration, trajectory, and device identity
• Produce splat appearance and reviewed physical geometry
• Author semantics, movable objects, affordances, and devices
• Expose capture/cooking defects and turn one real failure into a regression

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Synced from DIM-1387