Function assertNever

assertNever(value: never, message?: string): never
Exhaustiveness check for discriminated unions. Use in the default case of switch statements to ensure all cases are handled. TypeScript will report a compile-time error if a case is missing.
Parameters
- value: never
  The value that should be of type never if all cases are handled
- Optionalmessage: string
  Optional custom error message
Returns never
Never returns - always throws
Throws
Always throws with the unhandled value
Example
```
type Shape = { kind: 'circle'; radius: number } | { kind: 'square'; size: number };

function area(shape: Shape): number {
  switch (shape.kind) {
    case 'circle': return Math.PI * shape.radius ** 2;
    case 'square': return shape.size ** 2;
    default: return assertNever(shape.kind);
  }
}
```
- Defined in src/utils/errors.ts:34