fix(checkbox): ensure proper visual selection when navigating via VoiceOver in Safari (#30300)

Issue number: resolves internal

---------

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issue. -->

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## What is the current behavior?
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Currently, MacOS voice over on Safari does not recognize ion-checkbox
correctly and fails to highlight the element properly


## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->
By adding the role property to the host element, we're correctly
identifying ion-checkbox as a checkbox so Safari knows how to handle it.

## Does this introduce a breaking change?

- [ ] Yes
- [X] No

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  2. Update the BREAKING.md file with the breaking change.
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## Other information

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screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: Brandy Smith <brandyscarney@users.noreply.github.com>
Co-authored-by: Maria Hutt <thetaPC@users.noreply.github.com>

Author: 3 people

core/src/components/checkbox/checkbox.scss

@@ -111,8 +111,12 @@
   display: none;
 }
 
+/**
+ * The native input must be hidden with display instead of visibility or 
+ * aria-hidden to avoid accessibility issues with nested interactive elements.
+ */
 input {
-  @include visually-hidden();
+  display: none;
 }
 
 .native-wrapper {

core/src/components/checkbox/checkbox.tsx

@@ -31,6 +31,7 @@ import type { CheckboxChangeEventDetail } from './checkbox-interface';
 })
 export class Checkbox implements ComponentInterface {
   private inputId = `ion-cb-${checkboxIds++}`;
+  private inputLabelId = `${this.inputId}-lbl`;
   private helperTextId = `${this.inputId}-helper-text`;
   private errorTextId = `${this.inputId}-error-text`;
   private focusEl?: HTMLElement;
@@ -181,6 +182,15 @@ export class Checkbox implements ComponentInterface {
     this.ionBlur.emit();
   };
 
+  private onKeyDown = (ev: KeyboardEvent) => {
+    if (ev.key === ' ') {
+      ev.preventDefault();
+      if (!this.disabled) {
+        this.toggleChecked(ev);
+      }
+    }
+  };
+
   private onClick = (ev: MouseEvent) => {
     if (this.disabled) {
       return;
@@ -250,14 +260,23 @@ export class Checkbox implements ComponentInterface {
     } = this;
     const mode = getIonMode(this);
     const path = getSVGPath(mode, indeterminate);
+    const hasLabelContent = el.textContent !== '';
 
     renderHiddenInput(true, el, name, checked ? value : '', disabled);
 
+    // The host element must have a checkbox role to ensure proper VoiceOver
+    // support in Safari for accessibility.
     return (
       <Host
+        role="checkbox"
         aria-checked={indeterminate ? 'mixed' : `${checked}`}
         aria-describedby={this.getHintTextID()}
         aria-invalid={this.getHintTextID() === this.errorTextId}
+        aria-labelledby={hasLabelContent ? this.inputLabelId : null}
+        aria-label={inheritedAttributes['aria-label'] || null}
+        aria-disabled={disabled ? 'true' : null}
+        tabindex={disabled ? undefined : 0}
+        onKeyDown={this.onKeyDown}
         class={createColorClasses(color, {
           [mode]: true,
           'in-item': hostContext('ion-item', el),
@@ -271,7 +290,7 @@ export class Checkbox implements ComponentInterface {
         })}
         onClick={this.onClick}
       >
-        <label class="checkbox-wrapper">
+        <label class="checkbox-wrapper" htmlFor={inputId}>
           {/*
             The native control must be rendered
             before the visible label text due to https://bugs.webkit.org/show_bug.cgi?id=251951
@@ -291,9 +310,10 @@ export class Checkbox implements ComponentInterface {
           <div
             class={{
               'label-text-wrapper': true,
-              'label-text-wrapper-hidden': el.textContent === '',
+              'label-text-wrapper-hidden': !hasLabelContent,
             }}
             part="label"
+            id={this.inputLabelId}
           >
             <slot></slot>
             {this.renderHintText()}