Homogenize TypeScript types with online API reference

[brianmhunt]

Problem

The TypeScript type definitions in the source packages and the online API reference at tko.io/api/ are maintained separately. This means:

• Types in @tko/observable, @tko/computed, etc. may document signatures that the API page doesn't list
• The API page may describe behavior that the types don't enforce
• New APIs can be added to source without updating the docs, and vice versa

Proposal

1. Audit — compare the exported TypeScript types from @tko/build.reference against the API reference page
2. Single source of truth — either generate the API page from the types (e.g., TypeDoc or a custom script that reads .d.ts output), or establish a manual checklist that ties type changes to doc updates
3. CI check — optionally, a script that verifies every public export has a corresponding entry in api.md

Goal

A developer reading the API reference should see exactly the same function signatures, parameter types, and return types as their IDE shows from the TypeScript definitions.