Add explicit force replacement workflow

internal/config/validate.go

@@ -174,11 +174,11 @@ func validateTransferPolicy(errs ValidationErrors, context string, policy Transf
 	if policy.OnDestinationOlder != TransferActionReplace && policy.OnDestinationOlder != TransferActionFail {
 		errs = append(errs, context+".on_destination_older must be replace or fail")
 	}
-	if policy.OnDestinationNewer != TransferActionSkip && policy.OnDestinationNewer != TransferActionFail {
-		errs = append(errs, context+".on_destination_newer must be skip or fail")
+	if policy.OnDestinationNewer != TransferActionSkip && policy.OnDestinationNewer != TransferActionFail && policy.OnDestinationNewer != TransferActionReplace {
+		errs = append(errs, context+".on_destination_newer must be skip, replace, or fail")
 	}
-	if policy.OnConflict != TransferActionFail {
-		errs = append(errs, context+".on_conflict must be fail")
+	if policy.OnConflict != TransferActionFail && policy.OnConflict != TransferActionReplace {
+		errs = append(errs, context+".on_conflict must be fail or replace")
 	}
 	return errs
 }

internal/config/validate_test.go

@@ -47,6 +47,29 @@ func TestValidateChecksPublishTransformPolicy(t *testing.T) {
 	}
 }
 
+func TestValidateAcceptsForceReplacementTransferActions(t *testing.T) {
+	cfg := Config{Pipelines: []Pipeline{{
+		ID: "reports",
+		Source: Backend{
+			Backend: BackendLocal,
+			Path:    "/source",
+		},
+		Destinations: []Destination{{
+			ID:      "archive",
+			Backend: BackendLocal,
+			Path:    "/destination",
+			Transfer: TransferPolicy{
+				OnDestinationNewer: TransferActionReplace,
+				OnConflict:         TransferActionReplace,
+			},
+		}},
+	}}}
+	ApplyDefaults(&cfg)
+	if err := Validate(cfg); err != nil {
+		t.Fatalf("Validate() error = %v", err)
+	}
+}
+
 type publishTransformPolicyCase struct {
 	name      string
 	publish   PublishPolicy