Fix ESLint errors, bugs, and add gravity export

- Fix missing return in childRegistrationUtils.registerChild()
- Fix assertionUtils: assertNoNaN uses this.assertNoNaN
- Fix logger: nameModule uses this.nameModule
- Fix assetUtils: convert ESM to CommonJS
- Fix childRegistrationUtils_DEPRECATED: desc -> softwareType
- Add gravity export to index.js for rotatingMachine
- Fix ESLint errors across 18 files (no-undef, no-case-declarations,
  no-mixed-spaces-and-tabs, parsing errors)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/helper/childRegistrationUtils.js

@@ -39,7 +39,7 @@ class ChildRegistrationUtils {
 
     // IMPORTANT: Only call parent registration - no automatic handling and if parent has this function then try to register this child
     if (typeof this.mainClass.registerChild === 'function') {
-      this.mainClass.registerChild(child, softwareType);
+      return this.mainClass.registerChild(child, softwareType);
     }
 
     this.logger.info(`✅ Child ${name} registered successfully`);