test: blueprint codegen is untested against recursive Aiken types

[solidsnakedev]

Problem

Recursive Aiken types (e.g. a multisig script type that contains a list of itself) are not covered by the blueprint codegen pipeline. The gap spans three layers:

1. No Aiken source with a recursive type — there is no `.ak` file in the repo that defines a self-referencing type, so no `plutus.json` is ever generated from one.

2. No blueprint fixture for a recursive definition — `Blueprint.test.ts` has no test case where a definition's `$ref` points back to itself (directly or transitively). Without a fixture, whether the codegen emits correct `Schema.suspend(() => ...)` wrapping for self-references is untested.

3. No end-to-end codegen → encode/decode roundtrip test — `TSchema.recursive.test.ts` proves that `TSchema` itself handles recursive schemas correctly (e.g. MultisigScript from SundaeSwap), but there is no test that:

   • Takes a blueprint JSON with a recursive definition
   • Runs `generateFromBlueprint`
   • Validates the generated TSchema encodes and decodes recursive values correctly

Why it matters

The codegen already emits `Schema.suspend(() => ...)` for forward references (controlled by `useSuspend` in `CodegenConfig`), but this is only verified against non-recursive definitions in the current test suite. A true recursive type exercises a different code path — the suspend wrapping must appear on the field that references the containing type, not just a sibling definition — and this is untested.

Acceptance Criteria

• An Aiken contract with at least one recursive type is added (or a `plutus.json` fixture is added directly if adding Aiken source is out of scope)
• `Blueprint.test.ts` has a test case for a recursive definition that validates the generated code string contains correct `Schema.suspend` wrapping
• A roundtrip encode/decode test exercises the generated schema with a recursive value

[danbaruka]

Hi @solidsnakedev,
I can take this issue too.
Thanks.