Shorten the default retention, dramatically.

The original retention values were loosely based on Slack's retention, for lack of a more specific motivator. Today's election results have changed my views; the service now defaults to retention more in line with the needs of communities for which deep message history may be a risk:

* Unused channels expire after 7 days.
* Used channels expire when their last message expires (as before).
* Deleted channels are purged after 6 hours (which is in line with the purge behaviour of messages).
* Messages expire after 15 days.
* Deleted messages are purged after 6 hours (as before).

No changes have been made to token expiry.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/message/app.rs b/src/message/app.rs
index 137a27d..7bf68d1 100644
--- a/src/message/app.rs
+++ b/src/message/app.rs
@@ -80,8 +80,8 @@ impl<'a> Messages<'a> {
     }
 
     pub async fn expire(&self, relative_to: &DateTime) -> Result<(), sqlx::Error> {
-        // Somewhat arbitrarily, expire after 90 days.
-        let expire_at = relative_to.to_owned() - TimeDelta::days(90);
+        // Somewhat arbitrarily, expire after 15 days.
+        let expire_at = relative_to.to_owned() - TimeDelta::days(15);
 
         let mut tx = self.db.begin().await?;