Break usage down by request type or SDK #8186

Goal. Someone who has seen how much they used can find out where it came from.

Problem. The breakdown is a daily volume chart with By Endpoint and By SDK as separate tabs, so the four billable request types are never named as such.

Scope

• the breakdown gets its own section, with no plan limit on it, since an individual request type has no limit of its own
• rename By Endpoint to By request type. The rows are the four billable types
• a dimension menu: request type, SDK

Both dimensions derive from the response the charts already fetch, so they cost no extra requests. Project and environment are split out into their own issue: each costs one request per key, and usage-data is throttled at 5/min per user, so a multi-project org gets 429s and a list that ranks the rest wrongly.

Decide here. The menu covers the same ground as the existing tabs. If it replaces them, removing the old By SDK view and its sidebar is part of this work rather than left behind as dead code.

Done when

• the breakdown renders per dimension, and carries no limit line
• either the old tabs are gone, or there is a written reason they stayed