handleToolExecutionStart() flushed pending block replies and then called
onBlockReplyFlush() as fire-and-forget (`void`). This created a race where
fast tool results (especially media on Telegram) could be delivered before
the text block that preceded the tool call.
Await onBlockReplyFlush() so the block pipeline finishes before tool
execution continues, preserving delivery order.
Fixes#25267
Co-authored-by: Cursor <cursoragent@cursor.com>
SidQin-cyber
99d854db82