feat: redesign day picker with expandable calendar, status markers & Playwright E2E testing

- Replace modal calendar with inline expandable calendar widget integrated into the day picker.
- Add status indicator dots (attended/absent/pending) to month calendar grid matching day picker.
- Disable and gray out weekend days in calendar when weekend schedule is turned off.
- Redesign extend bar with integrated handle that aligns with the palette.
- Remove start-to-end timing on Today screen's class time rail, showing only start time.
- Implement Playwright E2E and visual testing suite with multi-screen capture scripts.
- Add cascade DELETE endpoints for subjects and versioned recurring timetable entries.

components/ui/screen.tsx

@@ -20,6 +20,7 @@ export function Screen({ children, scroll = true, edges = ['top'], style, conten
     <ScrollView
       testID={testID}
       style={styles.scroll}
+      contentInsetAdjustmentBehavior="automatic"
       contentContainerStyle={[styles.content, { paddingHorizontal: responsiveGutter }, contentContainerStyle, { paddingBottom: size.tabBar + spacing[6] }]}
       showsVerticalScrollIndicator={false}
       keyboardShouldPersistTaps="handled">