Types

Shapes accepted by VerifyIsEnum:

• a TypeScript enum (compiles to an object)
• a const object literal mapping names to primitive values
• a plain array of primitives

Element types are constrained to string | number because Array.prototype.includes — used under the hood — only handles value equality correctly for primitives. Object arrays would silently fail with reference equality, so they're rejected at compile time.

Resolves to the right decorator shape for the given options type.