feat: add support for ollama RAG providers

[nzlov]

• Added provider, model and endpoint configuration options for RAG service
• Updated RAG service to support Ollama providers
• Added Ollama embedding support and dependencies
• Improved environment variable handling for RAG service configuration

#1407

[nzlov]

LLM is still needed for parsing, so this should also be configurable.

[yetone]

‌‌‌‌LGTM, you might need to fix the py lint error:

pre-commit run --color=always --files $(find ./py -type f -name "*.py")

[yetone]

‌‌‌‌Thank you for the contribution! We should synchronize the documents and inform everyone on how to customize the RAG provider. Adding a few examples would be even better.

Additionally, will switching providers abruptly render the previous provider's embedding invalid? We should address this issue.

[nzlov]

Tell users in the documentation that they need to delete previous data when changing providers?

[yetone]

Tell users in the documentation that they need to delete previous data when changing providers?

Can we do this automatically?

[nzlov]

Due to pre-commit update version, need to wait for the third-party package to update and fix the error

[yetone]

‌‌‌‌Can you use pyright: ignore to temporarily ignore the error on this line?

[nzlov]

OK, thanks for your help