Feature Request: Allow manual model name input for OpenAI-compatible providers

[willwang0202]

Describe the bug

Describe the problem
When using the OpenAI Compatible provider, AIRI tries to auto-fetch the model list via /v1/models. However, some providers (e.g. MiniMax at api.minimax.io) do not expose this endpoint, resulting in a 404 error under Modules → Consciousness → Model, making it impossible to select a model.

Expected behavior
If the model list fails to load, there should be a fallback option to manually type in a model name/ID — similar to how many other AI tools handle this.

Steps to reproduce

1. Go to Settings → Providers → Add OpenAI Compatible
2. Set Base URL to https://api.minimax.io/v1 with a valid MiniMax API key
3. Go to Modules → Consciousness
4. Select the OpenAI Compatible provider
5. Model section shows: Error loading models — Remote sent 404 response: 404 page not found
6. There is no way to manually enter a model name

Suggested fix
Add a text input field as a fallback when the /v1/models endpoint returns an error, so users can manually type their desired model ID (e.g. MiniMax-M2.5).

System Info

- AIRI version: 0.8.4
- OS: macOS (Apple Silicon)
- Provider: MiniMax (`https://api.minimax.io/v1`)

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A, please open a GitHub Discussion instead.

Contributions

• I am willing to submit a PR to fix this issue
• I am willing to submit a PR with failing tests (actually just go ahead and do it, thanks!)

[NJX-njx]

I'd like to work on this. The plan is to add a fallback text input field for manual model name/ID entry when the /v1/models endpoint returns an error or is unavailable. This will involve modifying the provider configuration UI to detect fetch failures and show the manual input option.