Use modern JavaScript idioms

Favor modern JavaScript syntax and clean code practices to improve readability and maintainability. This includes:

1. Use template literals instead of string concatenation for clearer string interpolation: ```javascript // Preferred window.open(/${namespace}/${notebook}, “_blank”);

// Avoid window.open(“/” + namespace + “/” + notebook, “_blank”);

2. **Apply object destructuring** to reduce repetition and improve readability:
```javascript
// Preferred
const {contentDocument} = iframe;
contentDocument.addEventListener('click', handleEvent);

// Avoid
iframe.contentDocument.addEventListener('click', handleEvent);

1. Flatten nested conditionals when possible to reduce complexity: ```javascript // Preferred if (!queryParams || !queryParams[“ns”]) { return this.buildHref(href, this.queryParams); } return this.buildHref(href.replace(‘{ns}’, queryParams[“ns”]), queryParams);

// Avoid if (queryParams) { if (queryParams[“ns”]) { if (queryParams[“ns”] !== null) { // … } } }

4. **Remove unused code** including imports, commented-out code, and debug logging statements:
```javascript
// Remove before committing
console.log({own: (owned||[]).namespace, namespaces, ns: this.selected});

Maintaining these practices will lead to more consistent, readable, and maintainable code across the codebase.