feat: tambah sistem guide onboarding per fitur dengan GuideOverlay

- Buat komponen GuideOverlay dengan animasi fade+slide, arrow tooltip, dan dot indicator
- Buat hook useGuide untuk menyimpan state guide per fitur via AsyncStorage
- Sentralisasi semua step guide di lib/guideSteps.ts
- Pasang guide pada 12 halaman: village-calendar, project detail, banner, group, position, member, announcement, discussion, division calendar/document/discussion, dan division task detail
- Posisi card menggunakan cardTopRatio (rasio layar) untuk kompatibilitas berbagai ukuran device
- Tambah styles guide dan village calendar di constants/Styles.ts

constants/Styles.ts

@@ -1170,6 +1170,76 @@ const Styles = StyleSheet.create({
       fontStyle: 'italic',
    },
 
+   // guide overlay
+   guideOverlay: {
+      flex: 1,
+      backgroundColor: 'rgba(0,0,0,0.6)',
+      justifyContent: 'center',
+      alignItems: 'center',
+   },
+   guideCard: {
+      position: 'absolute',
+      left: 24,
+      right: 24,
+      borderRadius: 16,
+      padding: 20,
+      shadowColor: '#000',
+      shadowOffset: { width: 0, height: 4 },
+      shadowOpacity: 0.2,
+      shadowRadius: 12,
+      elevation: 8,
+   },
+   guideBadge: {
+      paddingHorizontal: 8,
+      paddingVertical: 3,
+      borderRadius: 20,
+   },
+   guideDotRow: {
+      marginTop: 16,
+      gap: 6,
+      justifyContent: 'center',
+   },
+   guideDot: {
+      width: 6,
+      height: 6,
+      borderRadius: 3,
+   },
+   guideButtonPrimary: {
+      flexDirection: 'row',
+      alignItems: 'center',
+      paddingHorizontal: 16,
+      paddingVertical: 8,
+      borderRadius: 20,
+   },
+   guideButtonSecondary: {
+      paddingHorizontal: 4,
+      paddingVertical: 8,
+   },
+   guideArrowUp: {
+      position: 'absolute',
+      top: -10,
+      marginLeft: -8,
+      width: 0,
+      height: 0,
+      borderLeftWidth: 8,
+      borderRightWidth: 8,
+      borderBottomWidth: 10,
+      borderLeftColor: 'transparent',
+      borderRightColor: 'transparent',
+   },
+   guideArrowDown: {
+      position: 'absolute',
+      bottom: -10,
+      marginLeft: -8,
+      width: 0,
+      height: 0,
+      borderLeftWidth: 8,
+      borderRightWidth: 8,
+      borderTopWidth: 10,
+      borderLeftColor: 'transparent',
+      borderRightColor: 'transparent',
+   },
+
    // village calendar & itemDateCalendar
    calendarDotRow: {
       flexDirection: 'row',