spell a self-referencing untagged map member as an index signature, where the mapped type cycled

[eburgos]

A self-recursive untagged enum whose recursive member is a map generates a TypeScript type alias that references itself through Partial<Record<string, Self>>. TypeScript resolves mapped types while it resolves the alias declaring them, so the alias is refused outright: error TS2456: Type alias circularly references itself. The array member never had this problem — only the map spelling did.

The fix is spelling-only: when the map's value type references the enclosing self type (the same test the zod renderer already applies for its z.lazy deferral), the member is written as the index-signature object it is equal to — { [key: string]: V | undefined } — which TypeScript resolves lazily. Every other map keeps the byte-identical Partial<Record<..>>: non-recursive maps, array-wrapped maps (the wrap already defers), and maps whose key does not spell as string or number (an index signature has no parameter type for those; that keyed-by-enum case is tracked separately). Zod and JSON Schema surfaces are untouched.

Tests pin the new spelling on the recursive fixture, the preserved spelling on a new non-recursive one, and the negative assertions on both; verified externally with tsc --strict: the new alias compiles clean, the old spelling reproduces TS2456. Full feature-combination matrix green.