Remote stream buffer gets separate timing for thinking blocks and first frames

What

When Claude Code runs as a remote session, it sends its reply out in small pieces as they are produced, called stream events. A buffer collects these pieces and sends them in batches, which is called a flush. Before, only tool input had its own flush interval (toolInputFlushMs). The buffer now has several new options and pieces of state for thinking text, the part where the model reasons before answering:

• thinkingFlushMs is a separate flush interval for thinking text.
• thinkingStartGoesAtOnce lets the start of a thinking block be sent at once instead of waiting for the next flush.
• thinkingBlockOpen tracks whether a thinking block is currently open.
• liveTwinWaitMs is a new wait setting, with matching state loggedLiveTwinWait.
• bufferHoldsFirstFrames tracks whether the buffer holds the first pieces of the stream, and a flush now reports whether it carried those first frames.
• The event uploader gains a waitsForMore() check in its backlog test.

The buffer also now counts how often a thinking start is sent at once and how often thinking text is flushed.

Why

This changes when thinking text is sent out to whoever is watching a remote session. The finding suggests it could make thinking appear sooner or less choppily, but the members do not show the effect.