feat: Add drag-and-drop slide reordering functionality

- Add reorderSlides function to useSlideOperations hook
- Update SlidesSidebar to handle drag-and-drop events
- Make SlideThumbnail components draggable with visual feedback
- Add CSS styles for drag states (dragged, drag-over, drag handle)
- Implement proper slide order management and persistence
- Add visual indicators for drag operations (opacity, transform, borders)
- Disable drag operations when saving to prevent conflicts
This completes the slide reordering feature from the user flows document.

Procfile

@@ -0,0 +1 @@
+web: npm run build && npm preview

public/themes-manifest.json

@@ -15,5 +15,5 @@
       "hasMasterSlide": true
     }
   },
-  "generated": "2025-09-12T14:15:01.593Z"
+  "generated": "2025-09-24T21:37:00.344Z"
 }

src/components/presentations/PresentationEditor.tsx

@@ -40,7 +40,7 @@ export const PresentationEditor: React.FC = () => {
     confirmDelete
   } = useDialog();
 
-  const { duplicateSlide, deleteSlide, saving } = useSlideOperations({
+  const { duplicateSlide, deleteSlide, reorderSlides, saving } = useSlideOperations({
     presentation,
     presentationId: presentationId || '',
     onPresentationUpdate: setPresentation,
@@ -176,6 +176,7 @@ export const PresentationEditor: React.FC = () => {
               onEditSlide={(slideId) => navigate(`/presentations/${presentationId}/slide/${slideId}/edit`)}
               onDuplicateSlide={duplicateSlide}
               onDeleteSlide={deleteSlide}
+              onReorderSlides={reorderSlides}
             />
 
             <div className="slide-editor-area">

src/components/presentations/SlidesSidebar.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useState } from 'react';
 import type { Slide } from '../../types/presentation.ts';
 import { SlideThumbnail } from './shared/SlideThumbnail.tsx';
 import './SlidesSidebar.css';
@@ -13,6 +13,7 @@ interface SlidesSidebarProps {
   onEditSlide: (slideId: string) => void;
   onDuplicateSlide: (index: number) => void;
   onDeleteSlide: (index: number) => void;
+  onReorderSlides: (fromIndex: number, toIndex: number) => void;
 }
 
 export const SlidesSidebar: React.FC<SlidesSidebarProps> = ({
@@ -24,8 +25,58 @@ export const SlidesSidebar: React.FC<SlidesSidebarProps> = ({
   onAddSlide,
   onEditSlide,
   onDuplicateSlide,
-  onDeleteSlide
+  onDeleteSlide,
+  onReorderSlides
 }) => {
+  const [draggedIndex, setDraggedIndex] = useState<number | null>(null);
+  const [dragOverIndex, setDragOverIndex] = useState<number | null>(null);
+
+  const handleDragStart = (e: React.DragEvent, index: number) => {
+    if (saving) return;
+
+    setDraggedIndex(index);
+    e.dataTransfer.effectAllowed = 'move';
+    e.dataTransfer.setData('text/plain', index.toString());
+
+    // Add drag image
+    if (e.currentTarget instanceof HTMLElement) {
+      e.currentTarget.style.opacity = '0.5';
+    }
+  };
+
+  const handleDragEnd = (e: React.DragEvent) => {
+    if (e.currentTarget instanceof HTMLElement) {
+      e.currentTarget.style.opacity = '';
+    }
+    setDraggedIndex(null);
+    setDragOverIndex(null);
+  };
+
+  const handleDragOver = (e: React.DragEvent, index: number) => {
+    e.preventDefault();
+    e.dataTransfer.dropEffect = 'move';
+
+    if (draggedIndex !== null && index !== draggedIndex) {
+      setDragOverIndex(index);
+    }
+  };
+
+  const handleDragLeave = () => {
+    setDragOverIndex(null);
+  };
+
+  const handleDrop = (e: React.DragEvent, toIndex: number) => {
+    e.preventDefault();
+
+    const fromIndex = draggedIndex;
+    if (fromIndex !== null && fromIndex !== toIndex && !saving) {
+      onReorderSlides(fromIndex, toIndex);
+    }
+
+    setDraggedIndex(null);
+    setDragOverIndex(null);
+  };
+
   return (
     <aside className="slide-sidebar">
       <div className="sidebar-header">
@@ -48,11 +99,18 @@ export const SlidesSidebar: React.FC<SlidesSidebarProps> = ({
             index={index}
             isActive={index === currentSlideIndex}
             isDisabled={saving}
+            isDragged={draggedIndex === index}
+            isDraggedOver={dragOverIndex === index}
             onClick={() => onSlideClick(index)}
             onDoubleClick={() => onSlideDoubleClick(slide.id)}
             onEdit={() => onEditSlide(slide.id)}
             onDuplicate={() => onDuplicateSlide(index)}
             onDelete={() => onDeleteSlide(index)}
+            onDragStart={(e) => handleDragStart(e, index)}
+            onDragEnd={handleDragEnd}
+            onDragOver={(e) => handleDragOver(e, index)}
+            onDragLeave={handleDragLeave}
+            onDrop={(e) => handleDrop(e, index)}
           />
         ))}
       </div>

src/components/presentations/shared/SlideThumbnail.css

@@ -114,4 +114,60 @@
 
 .thumbnail-action.delete:hover:not(:disabled) {
   background: var(--color-red-100);
-}
+}
+
+/* Drag and Drop Styles */
+.slide-thumbnail[draggable="true"] {
+  cursor: grab;
+}
+
+.slide-thumbnail[draggable="true"]:active {
+  cursor: grabbing;
+}
+
+.slide-thumbnail.dragged {
+  opacity: 0.5;
+  transform: rotate(2deg);
+  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
+}
+
+.slide-thumbnail.drag-over {
+  border-color: var(--color-blue-500);
+  background: var(--color-blue-50);
+  transform: translateY(-2px);
+  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.3);
+}
+
+.slide-thumbnail.drag-over::before {
+  content: '';
+  position: absolute;
+  top: -2px;
+  left: 0;
+  right: 0;
+  height: 2px;
+  background: var(--color-blue-500);
+  border-radius: 1px;
+}
+
+/* Drag Handle */
+.drag-handle {
+  position: absolute;
+  top: 50%;
+  right: 0.5rem;
+  transform: translateY(-50%);
+  color: var(--text-tertiary);
+  font-size: 0.875rem;
+  font-weight: bold;
+  opacity: 0;
+  transition: opacity 0.2s ease;
+  pointer-events: none;
+  z-index: 5;
+}
+
+.slide-thumbnail:hover .drag-handle {
+  opacity: 1;
+}
+
+.slide-thumbnail[draggable="false"] .drag-handle {
+  display: none;
+}

src/components/presentations/shared/SlideThumbnail.tsx

@@ -7,11 +7,18 @@ interface SlideThumbnailProps {
   index: number;
   isActive: boolean;
   isDisabled?: boolean;
+  isDragged?: boolean;
+  isDraggedOver?: boolean;
   onClick: () => void;
   onDoubleClick?: () => void;
   onEdit: () => void;
   onDuplicate: () => void;
   onDelete: () => void;
+  onDragStart?: (e: React.DragEvent) => void;
+  onDragEnd?: (e: React.DragEvent) => void;
+  onDragOver?: (e: React.DragEvent) => void;
+  onDragLeave?: (e: React.DragEvent) => void;
+  onDrop?: (e: React.DragEvent) => void;
 }
 
 export const SlideThumbnail: React.FC<SlideThumbnailProps> = ({
@@ -19,17 +26,50 @@ export const SlideThumbnail: React.FC<SlideThumbnailProps> = ({
   index,
   isActive,
   isDisabled = false,
+  isDragged = false,
+  isDraggedOver = false,
   onClick,
   onDoubleClick,
   onEdit,
   onDuplicate,
-  onDelete
+  onDelete,
+  onDragStart,
+  onDragEnd,
+  onDragOver,
+  onDragLeave,
+  onDrop
 }) => {
+  const handleClick = () => {
+    // Don't trigger click during drag operations
+    if (isDragged) return;
+    onClick();
+  };
+
+  const handleDoubleClick = () => {
+    // Don't trigger double-click during drag operations
+    if (isDragged || !onDoubleClick) return;
+    onDoubleClick();
+  };
+
+  const className = [
+    'slide-thumbnail',
+    isActive && 'active',
+    isDragged && 'dragged',
+    isDraggedOver && 'drag-over'
+  ].filter(Boolean).join(' ');
+
   return (
     <div
-      className={`slide-thumbnail ${isActive ? 'active' : ''}`}
+      className={className}
-      onClick={onClick}
+      draggable={!isDisabled}
-      onDoubleClick={onDoubleClick}
+      onClick={handleClick}
+      onDoubleClick={handleDoubleClick}
+      onDragStart={onDragStart}
+      onDragEnd={onDragEnd}
+      onDragOver={onDragOver}
+      onDragLeave={onDragLeave}
+      onDrop={onDrop}
+      title={`Slide ${index + 1}${isDragged ? ' (dragging...)' : ''}`}
     >
       <div className="thumbnail-number">{index + 1}</div>
       <div className="thumbnail-preview">
@@ -78,6 +118,12 @@ export const SlideThumbnail: React.FC<SlideThumbnailProps> = ({
           ✕
         </button>
       </div>
+
+      {!isDisabled && (
+        <div className="drag-handle" title="Drag to reorder">
+          ⋮⋮
+        </div>
+      )}
     </div>
   );
 };

src/hooks/useSlideOperations.ts

@@ -136,9 +136,48 @@ export const useSlideOperations = ({
     }
   };
 
+  const reorderSlides = async (fromIndex: number, toIndex: number) => {
+    if (!presentation || fromIndex === toIndex) return;
+
+    try {
+      setSaving(true);
+      onError('');
+
+      // Create updated presentation with reordered slides
+      const updatedPresentation = { ...presentation };
+      const newSlides = [...presentation.slides];
+
+      // Remove the slide from its current position
+      const [movedSlide] = newSlides.splice(fromIndex, 1);
+
+      // Insert it at the new position
+      newSlides.splice(toIndex, 0, movedSlide);
+
+      // Update slide order for all slides
+      newSlides.forEach((slide, index) => {
+        slide.order = index;
+      });
+
+      updatedPresentation.slides = newSlides;
+
+      // Save the updated presentation
+      await updatePresentation(updatedPresentation);
+
+      // Update local state
+      onPresentationUpdate(updatedPresentation);
+
+    } catch (err) {
+      loggers.presentation.error('Failed to reorder slides', err instanceof Error ? err : new Error(String(err)));
+      onError(err instanceof Error ? err.message : 'Failed to reorder slides');
+    } finally {
+      setSaving(false);
+    }
+  };
+
   return {
     duplicateSlide,
     deleteSlide,
+    reorderSlides,
     saving
   };
 };