refactor: rename root API modules to Types

[jderochervlk]

Summary

This is the shared-groundwork pass for the package simplification work.

Changes in this PR:

• rename all root src/*API.res type-holder modules to src/*Types.res
• rewrite repo references in src and tests to use the renamed root modules
• add type t and current exports to DOMAPI/Window.res and DOMAPI/Navigator.res
• preserve the existing folder structure
• avoid introducing any new include directives

Why

This establishes the baseline naming and module shape for the rest of the simplification work:

• *Types becomes the source of truth for shared API-local shapes
• concrete modules can become the ergonomic public entrypoints
• follow-up slice PRs can focus on unrelated open cleanup, primitive alias cleanup, and moving access away from Global.window / Global.navigator

Validation

Ran:

• npm run build
• npm test

The branch still has the existing warning 44 shadowing warnings, but build and tests pass.