refactor(ui-native): d3roNativePalette amber->main 개명 (WS-NATIVE)

- packages/ui-native theme.ts accent: amber->main, amberDim->dim, amberGlow->glow (값 보존)
- apps/mobile 20건 + apps/mobile-rn 18건 + ui-native 컴포넌트 9건 = 47 참조 치환
SKIP: Led/PhosphorText/Header color prop 'amber'(의미론적 컴포넌트 API, 별도 마이그레이션)
       green/greenGlow 키(amber계 범위外)
정책: docs/REFACTOR_POLICY.md DP1, 이식 인사이트 P7

apps/mobile/app/login.tsx

@@ -274,11 +274,11 @@ const styles = StyleSheet.create({
     fontFamily: Platform.OS === 'ios' ? 'System' : 'Roboto'
   },
   loginBtn: {
-    backgroundColor: P.accent.amber,
+    backgroundColor: P.accent.main,
     borderRadius: 12,
     paddingVertical: 14,
     alignItems: 'center',
-    shadowColor: P.accent.amber,
+    shadowColor: P.accent.main,
     shadowOffset: { width: 0, height: 0 },
     shadowOpacity: 0.3,
     shadowRadius: 10,
@@ -296,7 +296,7 @@ const styles = StyleSheet.create({
   warningBox: {
     borderWidth: 1,
     borderColor: 'rgba(255,92,53,0.3)',
-    backgroundColor: P.accent.amberDim,
+    backgroundColor: P.accent.dim,
     padding: 12,
     borderRadius: 8,
     marginTop: 8