[Feature request] List past sessions

[greatvovan]

Add -a option to list command:

  list					List all active sessions
    -a					Include past sessions (as long as they are in cache)

Output:

$ ./atch list -a
session3                 since 12s ago
session1   (terminated)  Jan 10  2025
session2   (terminated)  Mar 01 23:45
                         ^^^^^^^^^^^^
                         ls-style date for past sessions

The option will be useful in context of feature #19 to retrieve logs of past sessions.