Adds aria and keyboard interaction tests for the Dialog component (10 new tests, 53 total passing). Also fixes DialogContent to render with the `open` attribute so the <dialog> element is accessible in JSDOM.
Replace onMount+onCleanup with createEffect watching ctx.isOpen() and
ctx.modal(), so focusTrap/scrollLock/dismiss activate/deactivate
reactively on every open/close — including when forceMount keeps the
component mounted.
Note: role="dialog" was omitted; the project's Biome rules flag it as
redundant (noRedundantRoles) since <dialog> carries the implicit role.
Implements DialogRoot, Content, Title, Description, Trigger, Close, Portal, and Overlay parts with full context wiring, focus trap, scroll lock, and dismiss. Also fixes pre-existing TS6 exactOptionalPropertyTypes errors in create-disclosure-state and presence, and silences TS6.0 deprecation warnings via ignoreDeprecations.
