database: v72 upgrade requires manual intervention

has usage => sub { shift->extract_usage };

my $v72_migration_fyi = <<'EOF';

      /\

     /  \

    / !! \

   /  !!  \    MANUAL ACTION REQUIRED

  /   !!   \

 /          \

/     !!     \

+------------+

Travlynx 2.21 (or more specifically, database schema v72) persists per-journey

distance data in the database rather than computing it on-the-fly, as the

latter is quite expensive and could cause long load times on the history pages.

Adding this data for all journeys stored so far would take minutes to hours

depending on database size, and is therefore not done as part of this

migration. Please run the following command at your earliest convenience:

$ carton exec perl index.pl stats compute-distances

(adjust "carton exec" prefix, "sudo -u ...", environment variables, etc.

as necessary for your setup -- use the same invocation as for, e.g.,

"perl index.pl maintenance")

The command can operate while the travelynx services are running. Until this

post-migration script has completed, users may be confronted with invalid or

missing distance data in their history view for the current year and month.

There is a short window in which such invalid distances may be cached -- this

will happen whenever a user completes a journey and then opens the history page

for the current year or the current month. If you want to ensure that all

cached data is valid, you can follow up with the follow two commands:

$ carton exec perl index.pl stats purge

$ carton exec perl index.pl stats refresh-all

EOF

sub get_schema_version {

	my ( $db, $key ) = @_;

	my $version;

				update schema_version set version = 72;

			}

		);

		print $v72_migration_fyi;

	},

);