Fix lower-sticky-note accessibility for screen readers

Resolves CORE-1490

This commit addresses critical accessibility issues in the lower-sticky-note
component that prevented screen reader users from accessing the donation
banner content.

Changes made:

1. Added ARIA live region attributes (aria-live="polite" and aria-atomic="true")
   to the container div to ensure screen readers announce the dynamically
   loaded content when it appears on the page.

2. Changed role from "dialog" to "complementary" since this is a non-modal
   notification banner that doesn't trap focus.

3. Updated aria-label from generic "sticky note" to descriptive "Donation
   campaign announcement" to better convey the purpose to screen reader users.

4. Added aria-hidden="true" to all FontAwesome icon components to prevent
   screen readers from announcing icon content alongside button labels.

Files modified:
- src/app/layouts/default/lower-sticky-note/lsn-content.tsx
- src/app/components/put-away/put-away.tsx

Testing: This fix should be tested with NVDA/JAWS (Windows) and VoiceOver
(macOS) to verify that the banner content is announced when it appears and
that all interactive elements (dismiss button and donation link) are
accessible and operable with screen readers.

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

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: OpenStaxClaude

src/app/components/put-away/put-away.tsx

@@ -26,7 +26,7 @@ export default function PutAway(
             onKeyDown={closeUsingKeyboard}
             data-nudge-action='dismissed'
         >
-            <FontAwesomeIcon icon={faTimes} />
+            <FontAwesomeIcon icon={faTimes} aria-hidden="true" />
         </span>
     );
 }

src/app/layouts/default/lower-sticky-note/lsn-content.tsx

@@ -33,7 +33,7 @@ function NoteWithImage({bannerInfo}: {bannerInfo: BannerInfo}) {
                 <RawHTML className="blurb" html={bannerInfo.html_message} />
                 <a className="cta" href={bannerInfo.link_url} data-nudge-action="interacted">
                     {bannerInfo.link_text}
-                    <FontAwesomeIcon icon={faChevronRight} />
+                    <FontAwesomeIcon icon={faChevronRight} aria-hidden="true" />
                 </a>
             </div>
         </NoteContainer>
@@ -45,9 +45,9 @@ function NoteWithoutImage({bannerInfo}: {bannerInfo: BannerInfo}) {
         <NoteContainer withImage={false}>
             <RawHTML className="blurb" html={bannerInfo.html_message} />
             <a className="cta" href={bannerInfo.link_url} data-nudge-action="interacted">
-                <FontAwesomeIcon icon={faHeart} className="red-heart" />
+                <FontAwesomeIcon icon={faHeart} className="red-heart" aria-hidden="true" />
                 {bannerInfo.link_text}
-                <FontAwesomeIcon icon={faChevronRight} />
+                <FontAwesomeIcon icon={faChevronRight} aria-hidden="true" />
             </a>
         </NoteContainer>
     );
@@ -68,8 +68,10 @@ export default function LowerStickyNote({stickyData, PutAway}: {
             data-analytics-view
             data-analytics-nudge="donate"
             data-nudge-placement="banner"
-            role="dialog"
-            aria-label="sticky note"
+            role="complementary"
+            aria-label="Donation campaign announcement"
+            aria-live="polite"
+            aria-atomic="true"
         >
             <PutAway />
             {