fix(loader): add aria attributes for screen reader accessibility

[msmps]

Description

• Add role="status" and aria-label="Loading" to the Loader SVG component
• Resolves WCAG 2.1 SC 4.1.3 (Status Messages - Level AA) violation

Problem

The Loader component renders an SVG spinner without any accessibility attributes, making it completely invisible to screen readers. When used as a loading indicator (e.g., in buttons, page transitions, async operations), assistive technology users receive no indication that content is loading.

Screen readers skip over the Loader entirely - users hear nothing.

Solution

Add two ARIA attributes to the SVG element:

• role="status" - Indicates this is a live region for status updates
• aria-label="Loading" - Provides the accessible name announced by screen readers

Screen readers announce "Loading, status" when the Loader is present.

Testing

Verified with VoiceOver on macOS:

1. Enable VoiceOver (Cmd + F5)
2. Navigate to a Loader component (Ctrl + Option + →)
3. Confirm announcement: "Loading, status"