add non-commercial research license (model-release clause)

LICENSE

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+OriginLab Game-Depth Dataset License (Non-Commercial Research)
+Copyright (c) 2026 OriginLab.
+
+Permission is granted to use, copy, and adapt this dataset (the "Dataset") for
+NON-COMMERCIAL RESEARCH purposes only, subject to the conditions below.
+
+1. Non-commercial research use only. Any commercial use requires a separate
+   written agreement with OriginLab.
+
+2. Model-release requirement. If you train, fine-tune, or otherwise derive any
+   model using the Dataset (in whole or in part), you must publicly release that
+   model's weights together with a model card, under terms no more restrictive
+   than this license.
+
+3. Attribution. You must give appropriate credit and cite the Dataset (see the
+   Citation section of the dataset card).
+
+4. Redistribution of the Dataset or derivatives of it must include this license
+   and retain these conditions.
+
+5. No warranty. The Dataset is provided "AS IS", without warranty of any kind,
+   express or implied. OriginLab shall not be liable for any claim or damages
+   arising from use of the Dataset.
+
+By downloading or using the Dataset, you agree to these terms.