First "@" suggestions are now correct

Typing @ in the chat composer to reference a mesh node sometimes showed the wrong suggestions on the very first popup — typically the results for a previous search, or for the bare @ before you had finished typing the name. Only deleting and retyping the reference (or otherwise re-triggering the popup) brought up the right list.

The composer now tags every batch of streamed-in suggestions with the search text it answers, and the suggestion widget only shows a batch that matches what you are currently typing — anything stale is discarded and the correct search runs instead. The first popup reflects your actual input, every time.