feat: expand component library and documentation

[karngyan]

Summary

• add the full component expansion, including disclosure, navigation, selection, internationalized Calendar and DatePicker, context menu, file upload, and Sonner-style toast behavior
• reorganize the docs sidebar into animated, collapsible categories and document every public component
• use React Aria behavior with timezone-safe CalendarDate values from @internationalized/date

Verification

• 242 unit tests across 48 files
• package and docs typechecks
• production docs build with 48 prerendered pages
• 5 Playwright accessibility and contrast checks
• dark-mode and interaction QA against the local docs server
• Prettier formatting check