Add Dropdown Prototype

src/app/components/dropdown/dropdown.html

@@ -0,0 +1,20 @@
+<div class="dropdown-trigger">
+  <span class="placeholder">{{ selectedLabel }}</span>
+  <span class="chevron" [class.open]="isOpen()"></span>
+</div>
+
+@if (isOpen()) {
+  <ul class="dropdown-list" role="listbox">
+    @for (option of options(); track option.value; let i = $index) {
+      <li 
+        class="dropdown-item" 
+        role="option" 
+        [class.selected]="option.value === selectedValue()"
+        [class.focused]="i === focusedIndex()"
+        [attr.aria-selected]="option.value === selectedValue()"
+        (click)="selectOption(option); $event.stopPropagation()">
+        {{ option.label }}
+      </li>
+    }
+  </ul>
+}