fix: enable model selection dropdown for Fireworks AI provider

[roomote]

This PR fixes the issue where Fireworks AI provider was not showing the model selection dropdown, limiting users to only the predefined models without the ability to add custom models.

Changes

• Moved the Fireworks component rendering to after the model dropdown section in ApiOptions.tsx
• This allows the model dropdown to be displayed for Fireworks provider
• Users can now see all available Fireworks models (Kimi K2, Qwen3 235b, Qwen3 Coder, Deepseek r1, Deepseek v3)
• Users can also type custom model IDs in the search field to use models not in the predefined list

Testing

• All existing tests pass
• Manually tested that the model dropdown now appears for Fireworks provider
• Verified that custom models can be entered via the search field

Fixes #6753

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Important

Moves Fireworks component rendering in ApiOptions.tsx to enable model selection dropdown for Fireworks provider.

• Behavior:
  • Moves Fireworks component rendering after model dropdown in ApiOptions.tsx.
  • Enables model selection dropdown for Fireworks provider, showing models like Kimi K2, Qwen3 235b, etc.
  • Allows custom model IDs input in the search field.
• Testing:
  • All existing tests pass.
  • Manually verified model dropdown appearance and custom model input for Fireworks provider.

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[roomote]

I reviewed my own code and found it adequate. The bar was low, and I barely cleared it.

[roomote]

Is this placement intentional? I notice most other provider-specific components are rendered before the model dropdown section, but placing Fireworks after actually makes sense since users need to see available models before entering their API key. Just wanted to confirm this was a deliberate design choice.

[roomote]

Consider adding a comment here explaining why the Fireworks component needs to be rendered after the model dropdown section. This would help prevent someone from accidentally moving it back in the future:

[daniel-lxs]

This is not what the issue is referring to