use polyline when computing monthly/yearly distance travelled

Closes #40

lib/Travelynx.pm

@@ -1790,11 +1790,12 @@ sub startup {
 			}
 
 			my @journeys = $self->get_user_travels(
-				uid       => $uid,
-				cancelled => $opt{cancelled} ? 1 : 0,
-				verbose   => 1,
-				after     => $interval_start,
-				before    => $interval_end
+				uid           => $uid,
+				cancelled     => $opt{cancelled} ? 1 : 0,
+				verbose       => 1,
+				with_polyline => 1,
+				after         => $interval_start,
+				before        => $interval_end
 			);
 			my $stats = $self->compute_journey_stats(@journeys);
 

lib/Travelynx/Command/database.pm

@@ -997,6 +997,21 @@ my @migrations = (
 			}
 		);
 	},
+
+	# v20 -> v21
+	# After introducing polyline support, journey distance calculation diverged:
+	# the detail view (individual train) used the polyline, whereas monthly and
+	# yearly statistics were still based on beeline between intermediate stops.
+	# Release 1.16.0 fixes this -> ensure all caches are rebuilt.
+	sub {
+		my ($db) = @_;
+		$db->query(
+			qq{
+				truncate journey_stats;
+				update schema_version set version = 21;
+			}
+		);
+	},
 );
 
 sub setup_db {