feat: add GitHub Models provider and refactor model fetching with direct API fallback

- Add GitHub Models to supported OpenAI-compatible providers list
- Implement direct HTTP fallback for non-standard model responses
- Centralize model fetching logic in openai package
- Upgrade openai-go SDK dependency from v1.8.2 to v1.12.0
- Remove redundant model fetching code from openai_compatible package
- Add comprehensive GitHub Models setup documentation (700+ lines)
- Support custom models URL endpoint per provider configuration
- Add unit tests for direct model fetching functionality
- Update internationalization strings for model fetching errors
- Add VSCode dictionary entries for "azureml" and "Jamba"

README.md

@@ -73,6 +73,7 @@ Below are the **new features and capabilities** we've added (newest first):
 
 ### Recent Major Features
 
+- [v1.4.331](https://github.com/danielmiessler/fabric/releases/tag/v1.4.331) (Nov 23, 2025) — **Support for GitHub Models**: Adds support for using GitHub Models.
 - [v1.4.322](https://github.com/danielmiessler/fabric/releases/tag/v1.4.322) (Nov 5, 2025) — **Interactive HTML Concept Maps and Claude Sonnet 4.5**: Adds `create_conceptmap` pattern for visual knowledge representation using Vis.js, introduces WELLNESS category with psychological analysis patterns, and upgrades to Claude Sonnet 4.5
 - [v1.4.317](https://github.com/danielmiessler/fabric/releases/tag/v1.4.317) (Sep 21, 2025) — **Portuguese Language Variants**: Adds BCP 47 locale normalization with support for Brazilian Portuguese (pt-BR) and European Portuguese (pt-PT) with intelligent fallback chains
 - [v1.4.314](https://github.com/danielmiessler/fabric/releases/tag/v1.4.314) (Sep 17, 2025) — **Azure OpenAI Migration**: Migrates to official `openai-go/azure` SDK with improved authentication and default API version support