cli: add timestamp to output

With the Run storing the timestamp, it can be added to the CLI output
as well.

When pretty printing the timestamp, `chrono` is used to have a
date-time format.

Cargo.toml

@@ -12,6 +12,7 @@ edition = "2021"
 rust-version = "1.84.0"
 
 [dependencies]
+chrono = { version = "0.4", default-features = false }
 clap = { version = "4.5.41", features = ["derive", "wrap_help"] }
 indexmap = { version = "2.7.1", features = ["serde"] }
 nonempty = "0.11.0"