[FEATURE] Add extra usage metric to telemetry

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When managing my team, it would be great to have more granular views of when an how they need extra usage—e.g. which models, projects, or workflows the extra usage is associated with

Proposed Solution

Just like the usage metric, claude code should also report an extra_usage metric that tracks how much extra usage is billed for a given request (above the user's existing subscription plan).

Alternative Solutions

You can see extra usage in the console, but there's no way to graph it or break it down by any sort of detail

Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

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Additional Context

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