Centralises all Dialog prop interfaces and schemas in dialog.props.ts.
Adds DialogRootPropsSchema, DialogContentPropsSchema, and DialogMeta for
AI/MCP discovery. Sub-components now import types from the shared file.
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.
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.
