fix: remove PruneOrphanedMessages to preserve history within MAX_HISTORY

PruneOrphanedMessages deleted messages that lost their client_queues
references after PruneOldQueueEntries ran, even when those messages
were within the MAX_HISTORY limit. This made MAX_HISTORY meaningless
for low-traffic channels.

RotateChannelMessages already caps messages per target. Queue pruning
handles client_queues growth. Orphan cleanup is redundant.

Closes #40

README.md

@@ -1789,8 +1789,7 @@ skew issues) and simpler than UUIDs (integer comparison vs. string comparison).
 ### Data Lifecycle
 
 - **Messages**: Rotated per `MAX_HISTORY` — oldest messages beyond the limit
-  are pruned periodically per target (channel or DM). Orphaned messages (no
-  longer referenced by any client queue) are also removed.
+  are pruned periodically per target (channel or DM).
 - **Queue entries**: Pruned automatically when older than `QUEUE_MAX_AGE`
   (default 48h).
 - **Channels**: Deleted when the last member leaves (ephemeral).

internal/db/queries.go

@@ -1118,28 +1118,6 @@ func (database *Database) PruneOldQueueEntries(
 	return deleted, nil
 }
 
-// PruneOrphanedMessages deletes messages that are no
-// longer referenced by any client_queues row and returns
-// the number of rows removed.
-func (database *Database) PruneOrphanedMessages(
-	ctx context.Context,
-) (int64, error) {
-	res, err := database.conn.ExecContext(ctx,
-		`DELETE FROM messages WHERE id NOT IN
-		 (SELECT DISTINCT message_id
-		  FROM client_queues)`,
-	)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"prune orphaned messages: %w", err,
-		)
-	}
-
-	deleted, _ := res.RowsAffected()
-
-	return deleted, nil
-}
-
 // RotateChannelMessages enforces MAX_HISTORY per channel
 // by deleting the oldest messages beyond the limit for
 // each msg_to target. Returns the total number of rows

internal/handlers/handlers.go

@@ -245,18 +245,4 @@ func (hdlr *Handlers) pruneQueuesAndMessages(
 			)
 		}
 	}
-
-	orphaned, err := hdlr.params.Database.
-		PruneOrphanedMessages(ctx)
-	if err != nil {
-		hdlr.log.Error(
-			"orphan message cleanup failed",
-			"error", err,
-		)
-	} else if orphaned > 0 {
-		hdlr.log.Info(
-			"pruned orphaned messages",
-			"deleted", orphaned,
-		)
-	}
 }