add initial components and utility functions for simulation and builder modules

app/src/styles/layout/sidebar.scss

@@ -9,7 +9,7 @@
   background-color: var(--background-color);
   border-radius: #{$border-radius-extra-large};
   box-shadow: #{$box-shadow-medium};
-
+  z-index: #{$z-index-tools};
   .header-container {
     @include flex-space-between;
     padding: 10px;
@@ -179,6 +179,7 @@
   background-color: var(--background-color);
   border-radius: #{$border-radius-extra-large};
   box-shadow: #{$box-shadow-medium};
+  z-index: #{$z-index-tools};
 
   .header-container {
     @include flex-space-between;

app/src/styles/layout/toast.scss

@@ -1,9 +1,13 @@
+@use "../abstracts/variables" as *;
+@use "../abstracts/mixins" as *;
+
 .toast-container {
   position: fixed;
   z-index: 1000;
   display: flex;
   flex-direction: column;
   gap: 10px;
+  z-index: #{$z-index-ui-highest};
 }
 
 .toast-container.bottom-center {