(backend) de-index collections after inactivity

[eliott07]

Feature request Collections should be de-indexed from RAG provider to prevent bloating of their index that would lead to performance issues for us and our users

• Add a configurable inactivity time for conversations
• add a crone job that de-indexes collections from conversations that have not been use for a span of time bigger than the inactivity threshold
• Re-index conversations when a new message is sent to a conversation who's collection has been de-idexed
• Inform the user that this might take longer "Reprise de la conversation & de vos documents"

[providenz]

cf. #440

[eliott07]

@robin-lecomte what message should be displayed when conversations are being reindexed ?

[eliott07]

While projects are not the primary objective of this issue and will likely represent a lesser proportion of all collections, it would be interesting to look into de-indexing collections from projects also, with a longer timespan

[robin-lecomte]

Here is my proposal, ideally with a gauge. Otherwise, just the illustration and the text.

FIGMA