Cascade v1.1.0
+ Add theme accents: Blue, Graphite, Green, Orange, Pink, Purple, Red, Yellow
+ Add `Accent` property to `App` for setting and switching accent colors at runtime
+ Add `Notification` component with `Title`, `Subtitle`, `App`, `AppIcon`, `Icon`, `Duration`, and `Closed` properties
+ Add hover highlight to `PopUpButton` and `PullDownButton` menu options
+ Add default `Options` fallback for `PopUpButton`
! Removed `cascade.Window()` warning helper (use `app:Window()` directly)
! Removed hardcoded `TrackFill` color from dark theme slider (now driven by accent)
! Fixed `Tab` context key returning a broken `BackgroundColor3` function
! Fixed `Tab` type definition indentation in `types.luau`
! Fixed light theme `SwitchOn` hex casing inconsistency
! Internal theme refactor: themes now carry `_id` identifiers, `deepCopy` supports identifiers, and theme updates are handled by `updateThemes`/`parseAccent`
