Remote session transport gains read receipts, ack flushing and flush-on-first-delta

What

CCR is the connection Claude Code uses for remote sessions, where messages stream between Claude Code and another place such as the web. This release adds new options to it:

• inboundReadReceipts, a new transport option. When it is on, the filter for incoming streamed events changes, and 'processed' delivery reports are skipped for certain events. Before, every received event was reported as both received and processed as soon as it arrived.
• flushDeliveryAcks, a new transport method that sends pending delivery reports.
• streamEventFlushOnFirstDelta, a new worker setting, with a setStreamEventFlushOnFirstDelta setter on the transport. It is read from the remote switch tengu_ccr_stream_flush_on_first_delta and falls back to off when nothing is set. Nothing has been read about that switch.
• The read-receipt behaviour is controlled by a separate check that the findings could not identify.

The related switch tengu_ccr_event_hold_enabled falls back to on when nothing is set. No reading of it has been taken under this release.

Why

These options change how a remote session confirms that messages have arrived and been handled. Because they are controlled from Anthropic's servers and mostly fall back to off, most people will see no difference until they are switched on.