Preserve flag-based artifact regeneration arguments

internal/app/regenerate_artifacts.go

@@ -15,7 +15,7 @@ func RegenerateArtifacts(ctx context.Context, args []string, out io.Writer) erro
 	}
 
 	expanded := make([]string, 0, len(args)+5)
-	if len(args) > 0 {
+	if len(args) > 0 && !isCLIFlagToken(args[0]) {
 		expanded = append(expanded, args[0])
 		args = args[1:]
 	}

internal/app/regenerate_artifacts_test.go

@@ -40,6 +40,35 @@ func TestRegenerateArtifactsForwardsExactCanonicalRunArguments(t *testing.T) {
 	}
 }
 
+func TestRegenerateArtifactsForwardsSessionIDCompatibilityFlag(t *testing.T) {
+	original := runCommandFn
+	t.Cleanup(func() { runCommandFn = original })
+	var captured []string
+	runCommandFn = func(_ context.Context, args []string, _ io.Writer) error {
+		captured = append([]string(nil), args...)
+		return nil
+	}
+
+	code := Execute([]string{
+		"regenerate-artifacts",
+		"--config", "pipeline.yml",
+		"--session-id", "2026-05-03",
+		"--artifacts", "session_recap",
+	}, io.Discard, io.Discard)
+	if code != 0 {
+		t.Fatalf("Execute() code = %d, want 0", code)
+	}
+	want := []string{
+		"--force", "--from", "extract", "--through", "analyze",
+		"--config", "pipeline.yml",
+		"--session-id", "2026-05-03",
+		"--artifacts", "session_recap",
+	}
+	if !reflect.DeepEqual(captured, want) {
+		t.Fatalf("forwarded args = %#v, want %#v", captured, want)
+	}
+}
+
 func TestRegenerateArtifactsHelpDoesNotInvokeRun(t *testing.T) {
 	original := runCommandFn
 	t.Cleanup(func() { runCommandFn = original })