feat: add Mistral Devstral 2 model support

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This PR attempts to address Issue #9951 by adding support for the new Mistral Devstral 2 models.

Changes

New Models Added

• Devstral 2 (devstral-latest, devstral-2512): 256k context, $0.4/$2.0 pricing
• Devstral Small 2 (devstral-small-latest, labs-devstral-small-2512): 256k context, $0.1/$0.3 pricing

Configuration Updates

• Updated default model from codestral-latest to devstral-latest
• Changed default temperature from 1.0 to 0.2 based on Mistral Vibe CLI recommendations
• All new models configured with image support as specified in the issue

Implementation Details

• Added model definitions to packages/types/src/providers/mistral.ts
• Updated existing devstral-medium-latest to match new Devstral 2 specifications
• Maintained backward compatibility with existing models
• Updated tests to use the new default model

Testing

• ✅ All existing tests pass
• ✅ TypeScript compilation successful
• ✅ Linting checks pass

References

• Follows configuration patterns from Mistral Vibe CLI
• Temperature setting based on Mistral recommendations

Fixes #9951

Feedback and guidance are welcome!

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Rooviewer   See task on Roo Cloud

Review complete. No issues found.

The PR correctly adds support for the new Mistral Devstral 2 models as specified in issue #9951:

• Devstral 2 models (devstral-latest, devstral-medium-latest, devstral-2512) with correct 256k context and $0.4/$2.0 pricing
• Devstral Small 2 models (labs-devstral-small-2512, devstral-small-latest) with correct 256k context and $0.1/$0.3 pricing
• All models correctly configured with image support

Previous reviews

• fa5cd83: Review #1

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