fix(select): remove item focus style when there are no selected items only at ionic mode (#30750)

Issue number: resolves #

---------

This PR introduces improvements to the visual focus styling of Ionic
items when inside a select modal.

## What is the current behavior?
- The CSS variables `--background-focused` and
`--background-focused-opacity` were missing from `item.ionic.scss`,
which resulted in the native default outline focus style being applied
to focused items.
- When no item is selected, the focus style is currently applied to the
first list item by default, which we intend to change.

## What is the new behavior?
- Added missing focus css variables
- Hide the default focus style when there is no item selected

## NOTE
- This change will require an additional interaction to observe the
focus behavior when navigating through keyboard, since tap-based
navigation does not rely on focus styling.

## Does this introduce a breaking change?

- [ ] Yes
- [X] No

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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: ionitron <hi@ionicframework.com>
Co-authored-by: Maria Hutt <thetaPC@users.noreply.github.com>

core/src/components/item/item.ionic.scss

@@ -71,7 +71,6 @@ slot[name="end"]::slotted(*) {
 
 // Item: Focused
 // --------------------------------------------------
-
 :host(.ion-focused) .item-native::after {
   @include globals.border-radius(inherit);
   @include globals.position(0, 0, 0, 0);
@@ -112,3 +111,14 @@ slot[name="end"]::slotted(*) {
 :host(.item-lines-none) {
   --inner-border-width: #{globals.$ion-border-size-0};
 }
+
+// Item in Select Modal
+// --------------------------------------------------
+:host(.in-select-modal) {
+  --background-focused: #{globals.$ion-bg-neutral-subtlest-press};
+  --background-focused-opacity: 0;
+}
+
+:host(.in-select-modal.ion-focused) .item-native {
+  --border-radius: #{globals.$ion-border-radius-400};
+}

core/src/components/item/item.tsx

@@ -407,6 +407,7 @@ export class Item implements ComponentInterface, AnchorInterface, ButtonInterfac
             'item-control-needs-pointer-cursor': firstInteractiveNeedsPointerCursor,
             'item-disabled': disabled,
             'in-list': inList,
+            'in-select-modal': hostContext('ion-select-modal', this.el),
             'item-multiple-inputs': this.multipleInputs,
             'ion-activatable': canActivate,
             'ion-focusable': this.focusable,

core/src/components/select-modal/select-modal.ionic.scss

@@ -67,4 +67,9 @@ ion-content {
   --padding-end: #{globals.$ion-space-400} !important;
   /* stylelint-disable-next-line declaration-no-important */
   --padding-bottom: #{globals.$ion-space-1200} !important;
+
+  // Set the background to the focused element within a radio group only when there is a checked radio
+  &:has(.radio-checked) .ion-focused:not(.item-radio-checked) {
+    --background-focused-opacity: 1;
+  }
 }