fix #495: add schema preflight and DDL details

src/main/java/com/cloudhandson/vpdbackoffice/domain/schema/SchemaPreflightCheck.java

@@ -0,0 +1,28 @@
+package com.cloudhandson.vpdbackoffice.domain.schema;
+
+public record SchemaPreflightCheck(
+    String layer,
+    String itemName,
+    String objectType,
+    String status,
+    String detail,
+    String nextAction,
+    boolean sqlclRequired
+) {
+
+  public boolean ok() {
+    return "OK".equalsIgnoreCase(status);
+  }
+
+  public boolean warning() {
+    return "WARN".equalsIgnoreCase(status);
+  }
+
+  public boolean missing() {
+    return "MISSING".equalsIgnoreCase(status);
+  }
+
+  public boolean error() {
+    return "ERROR".equalsIgnoreCase(status);
+  }
+}