Clean up, add a deployment stage

Errors should be handled a bit more nicely now.

The SFTP part could also be done from deploy scripts like:

 scp -i {runner.ssh.identity} \
   -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no \
   {runner.ssh.user}@{runner.ssh.address%:*} -p {runner.ssh.address#*:}

but that is deemed way too annoying, so we do it from Go.

go.mod

@@ -3,9 +3,13 @@ module janouch.name/acid
 go 1.22.0
 
 require (
-	github.com/mattn/go-sqlite3 v1.14.22
-	golang.org/x/crypto v0.21.0
+	github.com/mattn/go-sqlite3 v1.14.24
+	github.com/pkg/sftp v1.13.7
+	golang.org/x/crypto v0.31.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
-require golang.org/x/sys v0.18.0 // indirect
+require (
+	github.com/kr/fs v0.1.0 // indirect
+	golang.org/x/sys v0.28.0 // indirect
+)