Wire up inventory select to ship state

Also mixed into this commit:

* Use returning drivers where possible
* Make the credits screen returnable via click

internal/flow/options.go

@@ -26,7 +26,7 @@ func (f *Flow) acceptOptions() {
 		log.Printf("Saving options to config failed: %v", err)
 		f.exit = err
 	} else {
-		f.setDriverNow(main)
+		f.returnToLastDriverNow(options)
 	}
 }