Please add the feature to "pin" files and individual messages (be it user or Lumo messages),
within the scope of one chat,
in order to protect them from summarisation AND deletion.

.

The reason is clear:
it's AWESOME that we now can continue using one chat for much longer, so that we don't have to interrupt our research or work so often any more.

BUT often times during the cleanup, important details, source files or parts of files, get lost to the summarisation.

.

P.s.:

My suggested feature having the scope of one chat would be perfectly fine for me,
however there are broader suggestions too:
https://protonmail.uservoice.com/forums/932842-lumo/suggestions/51504899-allow-users-to-manually-pin-items-to-persistent-me