fix: corrected the issues with the replicate integration

[Olyray]

Description

In #5561 there was a problem with the Replicate integration for Claude. I fixed the integration issue.

After fixing the specific claude integration issues, I noticed that it still wasn't working because there was a deeper issue with the Replicate integration. The API wasn't accepting the signal parameter. So I also fixed that issue and the integration is working fine.

Checklist

• I've read the contributing guide
• The relevant docs, if any, have been updated or created
• The relevant tests, if any, have been updated or created

Screen recording or screenshot

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Summary by cubic

Fixed the Replicate integration for Claude by removing the unsupported signal parameter, adding chat streaming, and mapping Claude 4 Sonnet correctly. This enables using Claude via Replicate in the app and improves error handling.

• Bug Fixes

  • Removed the signal parameter from Replicate API calls to match the API.
  • Corrected prompt handling for chat (system and user/assistant roles).
  • Added clear errors for invalid API keys and missing models.
  • Fixed docs tip to link to OpenRouter models.

• New Features

  • Streamed chat responses from Replicate with proper prompt formatting.
  • Enabled Claude 4 Sonnet selection under the Replicate provider in the model picker.

[cubic-dev-ai]

No issues found across 4 files