refactor: Extract reusable UI components and add TDD documentation

- Add comprehensive TDD documentation to CLAUDE.md with coverage requirements and examples
- Extract reusable UI components to frontend/src/components/ui/ (Modal, FormInput, Button, Alert, etc.)
- Add shared constants (schedulePresets) and utility hooks (useCrudMutation, useFormValidation)
- Update frontend/CLAUDE.md with component documentation and usage examples
- Refactor CreateTaskModal to use shared components and constants
- Fix test assertions to be more robust and accurate across all test files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/src/pages/Services.tsx

@@ -6,7 +6,7 @@ import { useServices, useCreateService, useUpdateService, useDeleteService, useR
 import { useResources } from '../hooks/useResources';
 import { Service, User, Business } from '../types';
 import { getOverQuotaServiceIds } from '../utils/quotaUtils';
-import CurrencyInput from '../components/CurrencyInput';
+import { CurrencyInput } from '../components/ui';
 
 interface ServiceFormData {
   name: string;