refactor: pecah lib/api.ts dan constants/Styles.ts per domain

- lib/api.ts (879 baris) → 13 file di lib/api/ per domain
- constants/Styles.ts (1.275 baris) → 10 file di constants/styles/ per domain
- tambah docs/FILE-HEALTH.md dan referensinya ke CLAUDE.md
- kedua file lama tetap sebagai re-export — zero breaking changes

constants/styles/button.styles.ts

@@ -0,0 +1,44 @@
+import { StyleSheet } from "react-native";
+
+const ButtonStyles = StyleSheet.create({
+   btnIconHeader: { padding: 3 },
+   btnFiturMenu: { padding: 13, borderRadius: 15, borderWidth: 1 },
+   btnRound: {
+      backgroundColor: '#1F3C88',
+      borderWidth: 0,
+      borderColor: '#1F3C88',
+      alignItems: 'center',
+      borderRadius: 30,
+      marginTop: 15,
+      paddingVertical: 10,
+   },
+   btnTab: {
+      alignItems: 'center',
+      paddingVertical: 5,
+      paddingHorizontal: 15,
+      borderRadius: 20,
+      flexDirection: 'row',
+      justifyContent: 'center',
+   },
+   btnLainnya: {
+      alignSelf: 'flex-start',
+      backgroundColor: '#1F3C88',
+      paddingVertical: 5,
+      marginVertical: 5,
+   },
+   btnDisabled: { backgroundColor: '#d6d8f6' },
+   btnMenuRow: { width: '33%', alignItems: 'center' },
+   btnMenuRowMany: { alignItems: 'center', marginHorizontal: 10 },
+   wrapBtnTab: {
+      justifyContent: 'space-between',
+      flexDirection: 'row',
+      marginBottom: 10,
+      borderRadius: 20,
+      padding: 5,
+      borderWidth: 1,
+   },
+   labelStatus: { paddingHorizontal: 15, borderRadius: 10 },
+   labelStatusSmall: { paddingHorizontal: 10, borderRadius: 10 },
+});
+
+export default ButtonStyles;