[FEATURE]: Display total cost for session

[goszczynskip]

Feature hasn't been suggested before.

• [x] I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

When running session with sub-agents the cost on the right includes only tokens of primary agent. It would be helpful to see the total cost of the session.

When I'm running more complex prompts with multiple sub-agents it's hard to monitor overall cost. I have to cycle through all sessions to check if some step isn't too expensive.

Features that would help me are:

• displaying individual sub-agent tokens + cost information on a sub-agent box.
• showing combined cost as an additional information on the right side panel

[github-actions[bot]]

This issue might be a duplicate of existing issues. Please check:

• #4895: Excluding reasoning context to reduce token usage

Feel free to ignore if none of these address your specific case.

[rekram1-node]

yep makes total sense, showing "real" total cost at the top level is something we rlly need