feat(openapi-generator): Improved OpenAPI schema generation for numeric and special types

This update enhances the OpenAPI specification generation with several improvements:

1. Numeric type handling:
- Changed `number` to `integer` type for integer schemas
- Added proper numeric constraints (minimum/maximum/multipleOf) for:
  - Regular numbers
  - BigInt values (now properly formatted as int64)
  - String-encoded numbers

2. Special type handling:
- Added proper format for UUID strings
- Improved date/time formatting
- Added JSON string format support
- Better handling of numeric unions

3. Parameter processing:
- Removed redundant `explode` and `style` parameters
- Added parent/paramName context for better schema inference
- Improved handling of numeric constraints in unions

Fix minimum/maximum bug in openapi.ts and add tests for numeric constraints

- Fixed a bug in openapi.ts where minimum and maximum values were swapped
- Added comprehensive tests for numeric constraints in openapi.ts
- Ensured all custom mappings in openapi.ts are properly tested
- Fixed the handling of undefined minimum and maximum values

Author: youngjungithub

packages/openapi-generator/src/knownImports.ts

@@ -297,7 +297,7 @@ export const KNOWN_IMPORTS: KnownImports = {
       E.right({
         type: 'string',
         format: 'number',
-        maximum: 0,
+        minimum: 0,
         decodedType: 'bigint',
       }),
     NonPositiveBigInt: () =>