chore: final pre-submission polish for JOSS

- Add CITATION.cff for GitHub citation support and Zenodo/JOSS integration
- Fix ossim reference URL in references.bib (was pointing to unrelated repo)
- Remove broken favicon reference from index.html (no public/ directory exists)
- Add meta description to index.html
- Fix sidebar title inconsistency: "Process Simulator" → "Process Scheduler Simulator"
- Rebuild dist.tar.gz with production assets

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

references.bib

@@ -36,7 +36,7 @@
   author       = {Robbins, Kay A.},
   title        = {{OS-sim}: A Graphical, Interprocess Operating System Simulator},
   year         = {2012},
-  howpublished = {\url{https://github.com/mayank-02/multithreading-library}},
+  howpublished = {\url{https://sourceforge.net/projects/oscsimulator/}},
   note         = {Used in OS coursework at several universities}
 }