[Build] refactor(phase-7): extract service_provider to filter helper + manager

# Mengurai Benang Kusut: Mempercantik Arsitektur `service_provider` Aku mengubah --- ### Raw Commit Data ## GitHub Update **Repository:** [MKWcorp/POS-DRW-Skincare](https://github.com/MKWcorp/POS-DRW-Skincare) **Author:** multimediadrw **Date:** 4/29/2026, 9:51:38 PM **Commit:** [`9442244`](https://github.com/MKWcorp/POS-DRW-Skincare/commit/9442244669dcfbe02e0fcf3182b7fbb436d86cbd) ### Commit Message refactor(phase-7): extract service_provider to filter helper + manager Phase 7: Final Cleanup - service_provider refactor Changes: - service_provider.dart: 500 → 145 lines (-355 lines, 71% reduction) - Created service_filter_helper.dart: 115 lines * ServiceFilterHelper class with static filter/sort methods * ServiceSort enum * applyFiltersAndSort utility method - Created service_manager.dart: 311 lines * ServiceManager class with all CRUD operations * Activity logging for all mutations * Bulk operations support Benefits: - Separation of concerns: filtering logic isolated - CRUD operations in dedicated manager class - Easier testing and maintenance - Consistent with Phase 0-6 architecture Validation: - flutter analyze: 0 errors, 24 info/warnings (non-blocking) - All service provider features preserved - Export statements ensure backward compatibility Total Refactor Progress (Phase 0-7): - 23+ screens modularized - service_provider extracted - ~8,000+ lines net reduction across all phases --- _This story was imported from historical commits._