[FEATURE REQUEST] Session Stats

[ddisisto]

I'd love to be able to have a running set of stats in a session about how many tokens in/out, even a breakdown of thinking and tool calls (by count, total token usage, etc). Furthermore, I'd like Claude to be able to reference this information directly (either context injection or even by tool call) so that I can advise token budgets for tasks, etc. Currently get a lot of time-based effort estimation during planning, that would really be more meaningful as token counts, given that Claude will go on to do the implementation in most cases.