age backups everywhere

ansible/roles/backup_source/tasks/main.yml

@@ -7,9 +7,11 @@
       - backup_source_dump_command | length > 0
       - backup_source_recipient | length > 0
       - backup_source_recipient is match('^age1[0-9a-z]{58}$')
+      - not (backup_source_stop_command | length > 0 and backup_source_start_command | length == 0)
     fail_msg: >-
       backup_source: '{{ backup_source_name | default("<unnamed>") }}' needs a name,
       description, dump command and a valid age recipient (age1... 62 chars).
+      backup_source_stop_command must be paired with backup_source_start_command.
     quiet: true
 
 # Declared here rather than assumed. Stage 1 installed it by hand; this is what