Adopt ConfigKit overlays for pipeline selection

internal/app/operator_helpers.go

@@ -23,7 +23,7 @@ type commonConfigFlags struct {
 	sessionPath       string
 	sessionID         string
 	previousSessionID string
-	profile           singletonStringFlag
+	overlay           singletonStringFlag
 	secretsDir        singletonStringFlag
 }
 
@@ -34,8 +34,8 @@ func addCommonConfigFlags(fs *flag.FlagSet, flags *commonConfigFlags) {
 	fs.StringVar(&flags.sessionPath, "session", "", "path to session.yml")
 	fs.StringVar(&flags.sessionID, "session-id", "", "session identifier")
 	fs.StringVar(&flags.previousSessionID, "previous-session-id", "", "expected previous session identifier")
-	flags.profile.name = "profile"
-	fs.Var(&flags.profile, "profile", "named pipeline profile")
+	flags.overlay.name = "overlay"
+	fs.Var(&flags.overlay, "overlay", "named pipeline overlay")
 	flags.secretsDir.name = "secrets-dir"
 	fs.Var(&flags.secretsDir, "secrets-dir", "secrets directory (optional; defaults beside pipeline.yml)")
 }
@@ -44,7 +44,7 @@ func (f commonConfigFlags) sessionOptions() config.SessionLoadOptions {
 	return config.SessionLoadOptions{
 		SessionID:         f.sessionID,
 		PreviousSessionID: f.previousSessionID,
-		Profile:           f.profile.pointer(),
+		Overlay:           f.overlay.pointer(),
 	}
 }