tighten-typescript-types

Replace boundary `any` with `unknown`, then validate or narrow before use with control-flow narrowing, type predicates performing real runtime checks, or discriminated unions. Annotate exported and serialization boundaries while letting inference handle honest local values.

Compile supported external consumers against the narrower declaration before changing public types. If a truthful narrower type is incompatible, tighten behind the existing boundary instead, and emit declarations to verify the contract.

Use `unknown` at boundaries where data arrives without proven shape, such as dynamic legacy data or external inputs. It forces validation or narrowing before use, keeping uncertainty visible rather than hiding it behind an assertion.

Use an assertion only when a runtime fact is established outside TypeScript's model, keep it at that boundary, and document the fact. Prefer `satisfies` to check values without discarding inference, and never use `@ts-ignore` to finish a pass.

No. Limit edits to changed files and directly used declarations that block an honest local type. Report pre-existing external errors separately rather than cleaning unrelated `any`, assertions, or legacy modules.