Function validatePostalCode

validatePostalCode(code: unknown): ValidationResult<PostalCodeInfo>
Validates a Sri Lankan postal code returning detailed ValidationResult.
Parameters
- code: unknown
  Postal code to check.
Returns ValidationResult<PostalCodeInfo>
{ isValid: true, data } with PostalCodeInfo, or { isValid: false, error, errors, code }.
Example
```
validatePostalCode('20000').isValid; // true
```
- Defined in postal-code/validator.ts:93