Update to dual license: Apache 2.0 (Research) + Commercial License

- Changed from Apache 2.0 only to dual license model
- Apache 2.0 for research, education, and non-commercial use
- Commercial license required for profit-making use
- Added citation requirement as condition of use for academic purposes
- Created CITATION.cff file for automatic citation suggestions
- Updated LICENSE, LICENSE.txt, README.md, and documentation
- Citation formats provided (BibTeX and text)
- Contact information for commercial licensing inquiries

LICENSE.txt

@@ -1,3 +1,14 @@
+DUAL LICENSE: APACHE 2.0 (RESEARCH) + COMMERCIAL LICENSE (COMMERCIAL USE)
+
+Copyright (c) 2024 Carlos Gutierrez
+
+================================================================================
+PART 1: APACHE 2.0 LICENSE (FOR RESEARCH AND NON-COMMERCIAL USE)
+================================================================================
+
+This software is licensed under the Apache License, Version 2.0 for research,
+academic, educational, and non-commercial purposes.
+
                                  Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
@@ -138,8 +149,8 @@
 
    6. Trademarks. This License does not grant permission to use the trade
       names, trademarks, service marks, or product names of the Licensor,
-      except as required for reasonable and customary use in describing the
-      origin of the Work and reproducing the content of the NOTICE file.
+      except as required for reasonable and customary use in describing
+      the origin of the Work and reproducing the content of the NOTICE file.
 
    7. Disclaimer of Warranty. Unless required by applicable law or
       agreed to in writing, Licensor provides the Work (and each
@@ -174,29 +185,76 @@
       incurred by, or claims asserted against, such Contributor by reason
       of your accepting any such warranty or additional liability.
 
-   END OF TERMS AND CONDITIONS
+   END OF APACHE LICENSE TERMS
 
-   APPENDIX: How to apply the Apache License to your work.
+================================================================================
+PART 2: COMMERCIAL USE RESTRICTIONS
+================================================================================
 
-      To apply the Apache License to your work, attach the following
-      boilerplate notice, with the fields enclosed by brackets "[]"
-      replaced with your own identifying information. (Don't include
-      the brackets!)  The text should be enclosed in the appropriate
-      comment syntax for the file format. We also recommend that a
-      file or class name and description of purpose be included on the
-      same "printed page" as the copyright notice for easier
-      identification within third-party archives.
+RESTRICTION: The Apache 2.0 license above applies ONLY to:
+- Academic research
+- Educational purposes
+- Personal projects
+- Open source contributions
+- Non-commercial use
 
-   Copyright [yyyy] [name of copyright owner]
+COMMERCIAL USE REQUIRES A SEPARATE LICENSE:
 
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
+For any commercial use, including but not limited to:
+- Commercial products or services
+- SaaS applications
+- Revenue-generating applications
+- Internal business use (for profit-making entities)
+- Any use that generates profit or revenue
+- Integration into commercial software products
 
-       http://www.apache.org/licenses/LICENSE-2.0
+You MUST obtain a commercial license from the copyright holder.
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-   implied. See the License for the specific language governing
-   permissions and limitations under the License.
+To obtain a commercial license, please contact:
+Email: carlos.gutierrez@carg.dev
+Subject: Commercial License Inquiry - SheepOp
+
+Please include in your inquiry:
+- Intended use case
+- Expected usage volume
+- Company/Organization name
+- Contact information
+
+Commercial licensing terms, including pricing, will be provided upon request.
+
+================================================================================
+CITATION REQUIREMENT FOR ACADEMIC USE
+================================================================================
+
+IMPORTANT: If you use this software in academic research, publications, or
+any scholarly work, you MUST cite this work.
+
+This is a condition of use under the Apache 2.0 license for academic purposes.
+
+Required Citation Format:
+
+@software{sheepop2024,
+  title = {SheepOp LLM: Transformer-based Language Model Implementation},
+  author = {Gutierrez, Carlos},
+  year = {2024},
+  url = {https://github.com/[your-username]/sheepOp},
+  version = {1.0}
+}
+
+Or in text format:
+
+Carlos Gutierrez. (2024). SheepOp LLM: Transformer-based Language Model 
+Implementation. https://github.com/[your-username]/sheepOp
+
+Failure to cite this work in academic publications constitutes a violation of
+the terms of use for academic purposes.
+
+================================================================================
+SUMMARY
+================================================================================
+
+✅ Research/Education/Non-commercial: Apache 2.0 (free)
+⚠️ Commercial use: Requires commercial license (contact for terms)
+📝 Citation: Please cite in academic publications
+
+For questions about licensing, contact: carlos.gutierrez@carg.dev