(release 1.13.0) token counts are zero after first message

[jamadeo]

After the first message in a new chat, the token counts are 0.

I've verified that they do come from goosed as zero:

"token_state":{"inputTokens":0,"outputTokens":0,"totalTokens":0,"accumulatedInputTokens":0,"accumulatedOutputTokens":0,"accumulatedTotalTokens":0}

[katzdave]

Investigating.

What I'm seeing is update_session_metrics does have the correct token state, but it doesn't get bubbled up to MessageEvent::Message in time.

On session reload we also see 0 token counts, but there neither of those code paths trigger. It should be loaded from the session directly there.

[katzdave]

#5606