feat: Expo scaffold + auth screens + core screens (#39-#46, #48)

constants/index.ts

@@ -0,0 +1,19 @@
+export const API_URL = process.env.EXPO_PUBLIC_API_URL ?? 'http://192.168.1.167:3001';
+
+export const COLORS = {
+  primary: '#2563EB',
+  primaryDark: '#1D4ED8',
+  danger: '#DC2626',
+  success: '#16A34A',
+  warning: '#D97706',
+  muted: '#6B7280',
+  background: '#F3F4F6',
+  white: '#FFFFFF',
+  black: '#111827',
+  border: '#E5E7EB',
+};
+
+export const STORAGE_KEYS = {
+  TOKEN: 'fiberops_token',
+  USER: 'fiberops_user',
+};