Add schedule preview dropdown styles and various improvements

- Add .schedule-preview-dropdown and .schedule-preview-item CSS classes
- Add .btn-schedule-preview badge styling
- Add preview functionality for entity list views
- Improve modal and dropdown styling
- Various JS and SCSS enhancements

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sources/scss/components/_entity-selector.scss

@@ -229,6 +229,55 @@
         }
     }
 
+    // Tabs row with actions (form-content layout)
+    .entity-selector-tabs-row {
+        display: flex;
+        align-items: stretch;
+        background: $es-slate-100;
+        border-bottom: 1px solid $es-border-color;
+        border-radius: $es-radius-lg $es-radius-lg 0 0;
+
+        .target-block-tabs {
+            flex: 1;
+            border-bottom: 0;
+            border-radius: $es-radius-lg 0 0 0;
+        }
+    }
+
+    // Expand/collapse toggle area (entire section is clickable)
+    .entity-selector-actions.btn-toggle-blocks {
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        padding: 0 $es-spacing-md;
+        background: $es-slate-100;
+        border-left: 1px solid $es-border-color;
+        color: $es-slate-400;
+        cursor: pointer;
+        transition: all $es-transition-fast;
+
+        &:hover {
+            background: $es-slate-200;
+            color: $es-primary;
+        }
+
+        .material-icons {
+            font-size: 20px !important;
+        }
+    }
+
+    // When expanded - highlight the toggle area
+    .entity-selector-trait:not(.blocks-collapsed) .entity-selector-actions.btn-toggle-blocks {
+        background: $es-primary-light;
+        border-left-color: $es-primary;
+        color: $es-primary;
+    }
+
+    // Blocks content wrapper (for form-content layout collapse)
+    .entity-selector-blocks-content {
+        // Inherits styles from condition-trait-body context
+    }
+
     // Block container
     .target-block-container {
         display: none;