cache results and instantly write to clipboard when using c/C in shell mode

it looks like in shell mode, the the c command takes the same time as querying, is it because it's re-fetching because there's no caching?

Start by tracing the shell-mode c/C command and the query path to determine whether each command re-fetches results. Verify how clipboard output is handled; done means cached results are reused and the command writes to the clipboard without waiting for another query.

Written by the indexing model from the issue text.