fix: Apply REMOVE_X_INTERNAL normalizer to nested inline properties

When REMOVE_X_INTERNAL=true is set, the normalizer removes the x-internal
extension from top-level schemas in components/schemas but fails to remove
it from inline object properties within those schemas.

This causes issues when:
1. A schema is imported cross-file (e.g., admin.yaml imports from chat.yaml)
2. That schema has an inline object property with x-internal: true
3. The inline property has type: object with nested properties

Result: TypeScript generator creates a type reference but no interface
definition, causing compilation errors.

This fix applies the same x-internal removal logic to normalizeProperties()
that already exists in normalizeComponentsSchemas(), ensuring inline
properties are handled consistently.

Fixes behavior for inline schemas with x-internal in cross-file imports.

Author: rc-glean

modules/openapi-generator/src/main/java/org/openapitools/codegen/OpenAPINormalizer.java

@@ -855,6 +855,13 @@ protected void normalizeProperties(Map<String, Schema> properties, Set<Schema> v
         }
         for (Map.Entry<String, Schema> propertiesEntry : properties.entrySet()) {
             Schema property = propertiesEntry.getValue();
+            
+            // remove x-internal if needed (same logic as normalizeComponentsSchemas)
+            if (property.getExtensions() != null && getRule(REMOVE_X_INTERNAL)) {
+                if (Boolean.parseBoolean(String.valueOf(property.getExtensions().get(X_INTERNAL)))) {
+                    property.getExtensions().remove(X_INTERNAL);
+                }
+            }
             Schema newProperty = normalizeSchema(property, new HashSet<>());
             propertiesEntry.setValue(newProperty);
         }