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/assertionUtils.js

@@ -16,7 +16,7 @@ class Assertions {
     assertNoNaN(arr, label = "array") {
         if (Array.isArray(arr)) {
             for (const el of arr) {
-                assertNoNaN(el, label);
+                this.assertNoNaN(el, label);
             }
         } else {
             if (Number.isNaN(arr)) {