Add Windows structure envelope

Author: mearvk

src/windows/WindowsStructure.java

@@ -0,0 +1,23 @@
+package windows;
+
+import java.time.Instant;
+import java.util.Map;
+
+/** Common envelope tying execution, program, directive, citizen, call, and choice together. */
+public record WindowsStructure(
+        WindowsExecution execution,
+        WindowsProgram program,
+        WindowsDirective directive,
+        WindowsCitizen citizen,
+        WindowsCall call,
+        WindowsChoice choice,
+        Instant createdAt,
+        Map<String, String> metadata) {
+    public WindowsStructure {
+        if (execution == null || program == null || directive == null || citizen == null
+                || call == null || choice == null || createdAt == null) {
+            throw new IllegalArgumentException("all Windows structure components are required");
+        }
+        metadata = Map.copyOf(metadata);
+    }
+}