chore: Remove GPT-4o, GPT-4o-mini, GPT-4-turbo, and Gemini 3 Pro Prev…

[Orinameh]

Summary

This PR removes several deprecated AI models from the providers configuration, specifically targeting the Gemini 3 Pro Preview model and removing GPT-4o, GPT-4o-mini, and GPT-4-turbo models to keep the available model list clean and up-to-date.

Related Issues

Changes

• Removed gemini-3-pro-preview model from the Google provider.
• Removed gpt-4o, gpt-4o-mini, and gpt-4-turbo models from the OpenAI provider.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactoring (no functional changes)
• CI/CD or build changes

Verification

Steps to reproduce / test

1. Check the list of models inside lib/ai/providers.ts.
2. Verify that gemini-3-pro-preview, gpt-4o, gpt-4o-mini, and gpt-4-turbo are no longer present.
3. Start the application and check the available models in the user interface to ensure the deprecated models no longer appear in the configurations.

What you personally verified

• Verified that the TypeScript definitions inside PROVIDERS remain valid and do not break the app compilation.

Evidence

• CI passes (pnpm check && pnpm lint && npx tsc --noEmit)
• Manually tested locally
• Screenshots / recordings attached (if UI changes)

Checklist

• My code follows the project's coding style
• I have performed a self-review of my code
• I have added/updated documentation as needed
• My changes do not introduce new warnings