Code evaluations fails silently when the ns declaration is invalid

Jack-in using a clj file with an illegal ns declaration like

```
(ns stuff.migrate
  [datomic.client.api :as d]
  )
```
brings Calva into a weired state, in which all code evaluations result in printing empty lines into repl output and no error appears.
see here:
https://clojurians.slack.com/archives/CBE668G4R/p1746724932683779

