Adopt modern JavaScript features (optional chaining, nullish coalescing)

[coderabbitai]

Goal: Modernize codebase with ES2020+ features.

Current Verbose Patterns

Manual undefined checks and verbose null checking throughout the code.

Modern Alternatives

• Use nullish coalescing (??) for default value assignment
• Use optional chaining (?.) for safe property access
• Cleaner object destructuring with defaults

Benefits

• More concise and readable code
• Reduces potential runtime errors
• Modern JavaScript best practices
• Better developer experience

Browser Support: Excellent modern browser support (Chrome 80+, Firefox 72+, Safari 13.1+)