feat: implement DOB input (year required) and dynamic age update

Issue Summary

Problem Statement

Proposed Solution

Test-Driven Development

Acceptance Criteria (Given-When-Then)

Scenario 1: [Scenario Name]

Given [initial context/state]
  And [additional preconditions]
 When [action is performed]
 Then [expected outcome]
  And [additional outcomes]

Scenario 2: [Scenario Name]

Given [initial context/state]
 When [action is performed]
 Then [expected outcome]

Test Cases

Test ID	Test Steps	Priority
TC-001	1. 2. 3.	High/Med/Low
TC-002	1. 2. 3.	High/Med/Low
TC-003	1. 2. 3.	High/Med/Low

Unit Test Requirements

Components/Functions to Test:

Module/Component	Function/Hook	Test Cases to Cover
e.g., `LoginForm.tsx`	`handleSubmit`	TC-001, TC-002

Test Assertions Required:

Renders correctly with initial state
Handles user input correctly
Validates input and shows errors
Calls API with correct payload
Handles loading state
Handles success response
Handles error response
Updates UI state appropriately

Implementation Details

Files to Change

File Path	Action	Purpose
`src/components/...`	Create/Modify
`src/pages/...`	Create/Modify
`src/types/...`	Create/Modify
`src/__tests__/...`	Create	Unit tests

Technical Considerations

UI/UX Requirements

Mockups/Wireframes:

Testing Strategy

Manual Testing

Test Environment:

Browser: [Chrome/Firefox/Safari/Edge]
Viewport: [Desktop/Tablet/Mobile]
User Role: [admin/coordinator/volunteer/patient/doctor]

Manual Test Steps:

Automated Testing

Unit Tests:

Component render tests
User interaction tests
API integration tests
Error handling tests

Integration Tests (if applicable):

Multi-component interaction tests
Route navigation tests

Test Data Requirements

// Example mock data
const mockTestData = {
  // Add required test data structure
}