assistant: handle empty input_schema for vercel providers flow

[sharon-wang]

• addresses Assistant: Bedrock models return error in Agent mode #9438
• takes the same approach as the equivalent code in the Anthropic provider flow to default the input schema type to 'object'

Release Notes

Bug Fixes

• Assistant: Bedrock models no longer error in Agent mode when using Copilot tools (Assistant: Bedrock models return error in Agent mode #9438)

QA Notes

1. auth to and select Amazon Bedrock as the provider
2. ensure positron.assistant.alwaysIncludeCopilotTools is enabled
3. send a message in the chat

Instead of this:

You should see:

and the Assistant Output channel should have a message like

[warning] Tool 'copilot_testFailure' is missing input schema type; defaulting to 'object'

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical

^{readme  valid tags}

[seeM]

Looks good!