UX: show image caption button on image hover (#670)

assets/stylesheets/modules/ai-helper/common/ai-helper.scss

@@ -482,17 +482,21 @@
 }
 
 // AI Image Caption Feature:
-.image-wrapper .button-wrapper {
+.image-wrapper {
+  .button-wrapper {
     .generate-caption {
       background: var(--tertiary-low);
       color: var(--tertiary);
       box-shadow: var(--shadow-dropdown);
       position: absolute;
       white-space: nowrap;
-    top: -3.15rem;
-    left: 0.75rem;
-    padding: 0.5em 0.75em;
+      top: -2rem;
+      left: 0.35rem;
+      padding: 0.33em 0.75em;
       transition: all 0.25s ease;
+      .discourse-no-touch & {
+        display: none;
+      }
 
       .d-icon {
         margin-right: 0.25rem;
@@ -516,6 +520,14 @@
       }
     }
   }
+  .discourse-no-touch & {
+    &:hover {
+      .button-wrapper .generate-caption {
+        display: block;
+      }
+    }
+  }
+}
 
 .ai-caption-popup {
   --ai-caption-popup-min-width: 20rem;