Modern null safety patterns

Leverage modern JavaScript features and utility functions for safer null/undefined handling. This reduces code verbosity while improving reliability.

Key practices:

1. Use optional chaining for nested property access: ```typescript // Instead of if (pattern && pattern.test(str)) { }

// Use if (pattern?.test(str)) { }

2. Apply nullish coalescing for default values:
```typescript
// Instead of
const ttl = value || defaultValue;

// Use
const ttl = value ?? defaultValue;

1. Utilize isNil() utility for explicit null/undefined checks: ```typescript // Instead of if (value === null || value === undefined) { }

// Use import { isNil } from ‘@nestjs/common/utils/shared.utils’; if (isNil(value)) { } ```

These patterns make code more concise while maintaining clear intent and proper null safety. They help prevent null reference errors and make null handling more consistent across the codebase.