feat(material/core): create focus-indicator structural styles loader

src/material/core/BUILD.bazel

@@ -25,6 +25,7 @@ ng_module(
         ":option/optgroup.css",
         ":internal-form-field/internal-form-field.css",
         ":ripple/ripple-structure.css",
+        ":focus-indicators/structural-styles.css",
     ] + glob(["**/*.html"]),
     deps = [
         "//src:dev_mode_types",
@@ -72,6 +73,12 @@ sass_library(
     ],
 )
 
+sass_binary(
+    name = "structural_styles_scss",
+    src = "focus-indicators/structural-styles.scss",
+    deps = [":core_scss_lib"],
+)
+
 sass_binary(
     name = "pseudo_checkbox_scss",
     src = "selection/pseudo-checkbox/pseudo-checkbox.scss",

src/material/core/focus-indicators/structural-styles.scss

@@ -0,0 +1,3 @@
+@use './private';
+
+@include private.structural-styling();

src/material/core/focus-indicators/structural-styles.ts

@@ -0,0 +1,23 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import {ChangeDetectionStrategy, Component, ViewEncapsulation} from '@angular/core';
+
+/**
+ * Component used to load structural styles for focus indicators.
+ * @docs-private
+ */
+@Component({
+  standalone: true,
+  selector: 'structural-styles',
+  styleUrl: 'structural-styles.css',
+  encapsulation: ViewEncapsulation.None,
+  template: '',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class _StructuralStylesLoader {}