What problem does this proposed feature solve?

This change would enable the model routers to provide better and more detailed dashboards for Roo Code users, including:

• Spending statistics on task level
• Spending statistics on mode level
• Statistics about min, avg and max turns per task
• Visibility around compression

Describe the proposed solution in detail

Add a new metadata argument to the createMessage method of the ApiHandler interface.
The metadata would allow for an optional Metadata type that contains the taskId and the current mode.

Different providers can then either forward this information when making the LLM chat completions call, or do nothing with it.

Technical considerations or implementation details (optional)

This should have 0 implications on the actual performance of the platform, as the data is already accessible from Task.ts, where most of the calls are made.

Describe alternatives considered (if any)

Idea no.1:
Try and get this information from within the relevant provider.
Why not:
Inverses the responsibilities and creates an unhealthy coupling.

Idea no.2:
Pass the information as a Record<string,any>.
Why not:
Passing discrete and type-checked values makes more sense while there's no fragmentation.

Additional Context & Mockups

No response

Proposal Checklist

• I have searched existing Issues and Discussions to ensure this proposal is not a duplicate.
• This proposal is for a specific, actionable change intended for implementation (not a general idea).
• I understand that this proposal requires review and approval before any development work begins.

Are you interested in implementing this feature if approved?

• Yes, I would like to contribute to implementing this feature.