Update citation title to descriptive model name

- Change title from 'sonar_core_1 (Revision 0712d08)' to 'Sonar Core 1 - Vietnamese Text Classification Model'
- Use consistent descriptive title across both README.md and System Card
- Improves citation clarity and academic referencing
- Maintains same DOI and Hugging Face Hub URL

🤖 Generated with [Claude Code](https://claude.ai/code)

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

README.md

@@ -329,7 +329,7 @@ If you use this model, please cite:
 ```bibtex
 @misc{undertheseanlp_2025,
     author       = { undertheseanlp },
-    title        = { sonar_core_1 (Revision 0712d08) },
+    title        = { Sonar Core 1 - Vietnamese Text Classification Model },
     year         = 2025,
     url          = { https://huggingface.co/undertheseanlp/sonar_core_1 },
     doi          = { 10.57967/hf/6599 },

Sonar Core 1 - System Card.md

@@ -271,7 +271,7 @@ If you use this model, please cite:
 ```bibtex
 @misc{undertheseanlp_2025,
     author       = { undertheseanlp },
-    title        = { sonar_core_1 (Revision 0712d08) },
+    title        = { Sonar Core 1 - Vietnamese Text Classification Model },
     year         = 2025,
     url          = { https://huggingface.co/undertheseanlp/sonar_core_1 },
     doi          = { 10.57967/hf/6599 },