docs: add citation section and fix stale org references

Add a Cite Us section to the README with BibTeX citation info, and
align it with docs/citation.md (author/organization: Semantica, 2026).
Update LICENSE and docs/project-license.md copyright holder to
Semantica, and replace the stale Hawksight-AI GitHub org slug with
semantica-agi across READMEs, plugin manifests, cookbook notebooks,
and GitHub templates.

.github/DISCUSSION_TEMPLATE/ideas.md

@@ -69,5 +69,5 @@ If you have ideas on how this could be implemented, please share.
 
 ---
 
-**Note**: For feature requests that are ready to be implemented, consider creating a [Feature Request issue](https://github.com/Hawksight-AI/semantica/issues/new?template=feature_request.md) instead.
+**Note**: For feature requests that are ready to be implemented, consider creating a [Feature Request issue](https://github.com/semantica-agi/semantica/issues/new?template=feature_request.md) instead.
 

.github/DISCUSSION_TEMPLATE/qa.md

@@ -46,8 +46,8 @@ If applicable, paste any error messages or describe unexpected behavior:
 
 ## Checklist
 
-- [ ] I have searched existing [discussions](https://github.com/Hawksight-AI/semantica/discussions) and [issues](https://github.com/Hawksight-AI/semantica/issues)
-- [ ] I have checked the [documentation](https://github.com/Hawksight-AI/semantica/tree/main/docs) and [FAQ](https://github.com/Hawksight-AI/semantica/blob/main/docs/faq.md)
+- [ ] I have searched existing [discussions](https://github.com/semantica-agi/semantica/discussions) and [issues](https://github.com/semantica-agi/semantica/issues)
+- [ ] I have checked the [documentation](https://github.com/semantica-agi/semantica/tree/main/docs) and [FAQ](https://github.com/semantica-agi/semantica/blob/main/docs/faq.md)
 - [ ] I have provided a minimal code example (if applicable)
 - [ ] I have included error messages (if applicable)
 - [ ] I have provided environment details