Summary

This PR implements three TypeScript ESLint rules for the rslint project:

1. @typescript-eslint/no-non-null-assertion

TypeScript's ! non-null assertion operator asserts to the type system that an expression is non-nullable, as in not null or undefined. Using assertions to tell the type system new information is often a sign that code is not fully type-safe. It's generally better to structure program logic so that TypeScript understands when values may be nullable.

interface Example {
  property?: string;
}

declare const example: Example;
const includesBaz = example.property!.includes('baz');

Test Coverage

• ✅ All TypeScript tests passing
• ✅ All Go unit tests passing
• ✅ Integration tests with rslint CLI
• ✅ Edge cases and error conditions covered

Quality Checks

• ✅ Go vet and fmt compliance
• ✅ Golangci-lint static analysis passing
• ✅ TypeScript type checking
• ✅ ESLint and formatting checks
• ✅ CI pipeline validation