Simplify DOM, event, and observer module surfaces

[jderochervlk]

Parent: #237

Blocked by: #239

Summary

Update the DOM and event-related surface to follow the new *Types + concrete-module t contract.

Scope

• Prelude
• Event
• DOM
• UIEvents
• IntersectionObserver
• MutationObserver
• ResizeObserver
• ViewTransitions
• related DOM/observer tests

Files

• src/Prelude.res
• src/Prelude/*.res
• src/EventTypes.res
• src/EventAPI/*.res
• src/DOMTypes.res
• src/DOMAPI/*.res
• src/UIEventsTypes.res
• src/UIEventsAPI/*.res
• src/IntersectionObserverTypes.res
• src/IntersectionObserverAPI/*.res
• src/MutationObserverTypes.res
• src/MutationObserverAPI/*.res
• src/ResizeObserverTypes.res
• src/ResizeObserverAPI/*.res
• src/ViewTransitionsTypes.res
• src/ViewTransitionsAPI/*.res
• tests/DOMAPI/*.res
• tests/IntersectionObserverAPI/*.res
• tests/MutationObserverAPI/*.res

Checklist

• Add type t = ... = { ... } to the event and DOM foundation modules
• Add selective secondary re-exports where they belong in the concrete module surface
• Remove trivial aliases such as DOM's voidFunction while keeping meaningful callback contracts like frameRequestCallback
• Update DOM-facing tests to use renamed root type modules and Window.current where needed
• Verify the diff adds no new include directives
• Run npm run build
• Run npm test

Acceptance Criteria

• concrete DOM/event modules expose t
• selective secondary re-exports exist only where justified
• unrelated opens are reduced or removed in the edited surface
• no new include directives are introduced
• DOM/observer tests pass under the new module naming and access pattern

[jderochervlk]

Fixed by #245