feat: redesign section member dan fix warna dimmed

- SectionMember & SectionMemberTask: ganti BorderBottomItem dengan card item
  custom (avatar + nama + badge jabatan), skeleton baru, label jumlah anggota
- Colors.ts: hapus suffix alpha '#707887ff' → '#707887' pada warna dimmed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

constants/Colors.ts

@@ -13,7 +13,7 @@ export const Colors = {
     tabActive: '#2563EB',
     header: '#234881',
     homeGradient: '#346CC4',
-    dimmed: '#707887ff',
+    dimmed: '#707887',
     success: '#40C057',
     warning: '#FBBF24',
     error: '#F87171',