[ENHANCEMENT] Implement screen reader support and ARIA semantics

Describe the current behavior

The application lacks proper screen reader support and ARIA semantics. Interactive elements, dynamic content, and UI components don't have proper ARIA attributes or roles, making the application inaccessible to users relying on assistive technologies.

Describe the desired improvement

• Add semantic HTML structure with proper heading hierarchy
• Implement ARIA landmarks for main regions (main, navigation, complementary)
• Add proper ARIA labels and roles for all interactive components
• Implement ARIA live regions for dynamic content updates
• Add descriptive labels for form controls and interactive elements
• Ensure proper announcement of modal dialogs and state changes
• Add meaningful alt text for all images and icons
• Implement proper error announcements for form validation

Why is this improvement important?

Proper screen reader support and ARIA implementation are essential for users with visual impairments. This enhancement ensures compliance with WCAG guidelines and makes the application truly accessible to all users.

Alternatives Considered

• Using role="application" (rejected as it overrides native semantics)
• Custom screen reader announcements (unnecessary with proper ARIA)
• Separate text-only version (maintenance burden)

Additional context

Implementation should focus on all components, particularly:

• Form components in the resume editor
• Modal dialogs and popups
• Dynamic content updates
• Navigation elements