backup: skip ./sessions in nightly tar (matches reshape checkpoint)

templates/backup-cronjob.yaml

@@ -136,7 +136,11 @@ spec:
                   # treats absent filestore object as "no filestore
                   # captured for this snapshot" (older backups).
                   if [ -d /var/lib/odoo ] && [ -n "$(ls -A /var/lib/odoo 2>/dev/null)" ]; then
-                    tar -czf - -C /var/lib/odoo . \
+                    # Exclude ./sessions — HTTP session cache,
+                    # unique per cookie, expires on Odoo restart
+                    # anyway. Including it bloats the archive and
+                    # slows backups by minutes on busy instances.
+                    tar -czf - --exclude=./sessions -C /var/lib/odoo . \
                       | aws --endpoint-url "$S3_ENDPOINT" s3 cp - "s3://${S3_BUCKET}/${FS_KEY}"
                   else
                     echo "(filestore empty; skipping archive)"