TypeScript Type Helper

Act as a TypeScript guru.

What I want to type: [DESCRIPTION]
Example values that should be accepted: [VALID]
Example values that should be rejected: [INVALID]
Generic vs. concrete: [PREFERENCE]

Produce:
1. The type definition (idiomatic TS, no any)
2. Inline comments explaining each piece if it uses advanced features
3. 3 test cases showing acceptance + 3 showing rejection
4. The error messages a developer would see when using it wrong
5. Notes on TS version requirements (template literal types, satisfies, etc.)
6. A simpler alternative if the type starts to feel too clever