{
  "stages": [
    {
      "stage": "01_Before_Z91_505",
      "reopened": true,
      "controller": "bezier_scale",
      "key_count": 2,
      "samples": [
        {
          "frame": 0,
          "scale_percent": [
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            100.0,
            100.0
          ],
          "position": "[0,65.956,40]"
        },
        {
          "frame": 50,
          "scale_percent": [
            100.0,
            100.0,
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          ],
          "position": "[0,65.956,40]"
        },
        {
          "frame": 100,
          "scale_percent": [
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            100.0,
            91.50500297546387
          ],
          "position": "[0,65.956,40]"
        }
      ]
    },
    {
      "stage": "02_After_Z100",
      "reopened": true,
      "controller": "bezier_scale",
      "key_count": 2,
      "samples": [
        {
          "frame": 0,
          "scale_percent": [
            100.0,
            100.0,
            100.0
          ],
          "position": "[0,65.956,40]"
        },
        {
          "frame": 50,
          "scale_percent": [
            100.0,
            100.0,
            100.0
          ],
          "position": "[0,65.956,40]"
        },
        {
          "frame": 100,
          "scale_percent": [
            100.0,
            100.0,
            100.0
          ],
          "position": "[0,65.956,40]"
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      ]
    }
  ],
  "source": "课堂教学视频5.mp4",
  "confirmed": [
    "03:30 key2 Time100 X100 Y100 Z91.505",
    "03:44 same key Time100 X100 Y100 Z100"
  ],
  "supplemented": [
    "frame0 scale100 inferred from graph",
    "inherited default scale controller tangents; exact tangent choices unverified",
    "prior static shader and supplemented camera/room retained, not teacher appearance match"
  ],
  "pending": [
    "initial scale and coordinate-system operations",
    "later Curve Editor tools",
    "assessment integration"
  ]
}