feat(ui): replace emoji icons with fontawesome icons

Add Font Awesome dependency and replace all emoji icons with corresponding Font Awesome icons across components. This provides better visual consistency and scalability.

src/views/Instances.vue

@@ -2,6 +2,9 @@
     <div class="instances-page">
         <div class="page-header">
             <h2>Instance Management</h2>
+            <button class="add-btn" @click="showAddModal = true">
+                <i class="fas fa-plus" aria-hidden="true"></i> Add Instance
+            </button>
         </div>
         <div class="instances-grid">
             <div