[Feature Request]: Enhanced UI Modularity

### Problem Description

I'm extremely grateful for the amazing work that has gone into NextChat so far! However, I believe that the current UI can be improved to be more modular and future-proof. Currently, the lack of modularity limits the customization options for users, making it difficult to adapt to changing requirements. I'd like to see NextChat's UI evolve to allow for more flexibility and user control.

### Solution Description

I propose these UI improvements:

1. **LLM Parameter Management:** Allow users to add, remove, enable, or disable LLM parameters (e.g., `temp_k`, `max_tokens`) directly through the UI.

2. **Independent Title & Summary Generation:** Decouple title and summary generation, allowing users to select different models for each task via the UI.

3. **Editable System Prompts:** Enable users to edit the system prompts injected into the "Inject System Prompts" section from the UI.

4. **Customizable Provider Management:** Allow users to add, name, delete, and manage OpenAI API-compatible providers (e.g., OpenRouter, Groq) via the UI.

5. **Editable Model Lists:** Enable users to edit the default model lists for each provider and mark models with vision support.

To ensure clarity, these advanced features could be accessible after enabling an "Editor Mode," catering to both basic and advanced users.

### Alternatives Considered

_No response_

### Additional Context

_No response_