Orval implementation

[rishikamtam12]

note:

Generated output structure differs slightly from the original expectation.Orval generates schema-based type files with a shared index rather than a single flat generated.types.ts file.

Why this approach was kept:

• Aligns with Orval’s default and recommended output
• Scales better as the API grows (one file per schema instead of one large file)

[bamarler]

Great work, this looks nice. Just please make sure that the checks pass.

Also, in the issue I said that we should use a zod plugin. Ideally Orval can generate that, but if you found that it's not possible we can discuss if it's necessary.