Implement slide deletion and duplication functionality

- Add complete slide deletion with smart confirmation messages
- Implement slide duplication that copies layout, content, and notes
- Handle edge cases for navigation after deletion/duplication
- Add proper slide order management and renumbering
- Include comprehensive error handling and user feedback
- Support deleting last slide, only slide, and middle slides
- Navigate intelligently after operations (to duplicated slide, adjusted position after deletion)
- Add improved confirmation dialogs with context-aware messaging
- Integrate with existing presentation storage and state management
- Replace placeholder TODO implementations with full functionality

Features completed:
✅ User can delete slides from presentation
✅ User gets confirmation before slide deletion
✅ Slide order adjusts automatically
✅ User can duplicate existing slides copying layout and content
✅ Smart navigation maintains user context after operations
✅ Robust error handling with proper user feedback

🤖 Generated with [Claude Code](https://claude.ai/code)

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

USERFLOWS.md

@@ -35,6 +35,7 @@
 - [x] User can add presentation notes to slide
 - [x] User can see miniature preview of slide live while editing
 - [x] User can save slide (auto-saves presentation)
+- [x] User can duplicate an existing slide copying it's layout and content.
 
 ### Edit Existing Slide
 - [x] User can click on existing slide to edit
@@ -43,6 +44,7 @@
 - [x] User can exit slide editing mode without saving changes in an obvious way
 - [x] User can edit presentation notes
 - [x] Changes auto-save to presentation
+- [ ] User can edit slide content without preview if desired by clicking inside content slot areas
 
 ### Remove Slide
 - [ ] User can delete slides from presentation
@@ -53,3 +55,8 @@
 - [ ] User can preview individual slides
 - [ ] User can view slides in presentation mode
 - [ ] User can navigate between slides in preview
+
+### Slide Order Management
+- [ ] User can reorder slides via drag-and-drop
+- [ ] User can see slide order visually in editor
+- [ ] Slide order automatically saves when changed

src/components/presentations/PresentationEditor.tsx

@@ -2,7 +2,7 @@ import React, { useState, useEffect } from 'react';
 import { useParams, useNavigate, Link } from 'react-router-dom';
 import type { Presentation } from '../../types/presentation';
 import type { Theme } from '../../types/theme';
-import { getPresentationById } from '../../utils/presentationStorage';
+import { getPresentationById, updatePresentation } from '../../utils/presentationStorage';
 import { getTheme } from '../../themes';
 import './PresentationEditor.css';
 
@@ -88,16 +88,47 @@ export const PresentationEditor: React.FC = () => {
   const duplicateSlide = async (slideIndex: number) => {
     if (!presentation) return;
     
+    const slideToDuplicate = presentation.slides[slideIndex];
+    if (!slideToDuplicate) return;
+    
     try {
       setSaving(true);
+      setError(null);
       
-      // TODO: Implement slide duplication
-      console.log('Duplicate slide functionality to be implemented');
-      alert('Slide duplication will be implemented next.');
+      // Create a duplicate slide with new ID
+      const duplicatedSlide = {
+        ...slideToDuplicate,
+        id: `slide_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+        order: slideIndex + 1 // Insert right after the original
+      };
+      
+      // Create updated presentation with the duplicated slide
+      const updatedPresentation = { ...presentation };
+      const newSlides = [...presentation.slides];
+      
+      // Insert the duplicated slide after the original
+      newSlides.splice(slideIndex + 1, 0, duplicatedSlide);
+      
+      // Update slide order for all slides after the insertion point
+      newSlides.forEach((slide, index) => {
+        slide.order = index;
+      });
+      
+      updatedPresentation.slides = newSlides;
+      
+      // Save the updated presentation
+      await updatePresentation(updatedPresentation);
+      
+      // Update local state
+      setPresentation(updatedPresentation);
+      
+      // Navigate to the duplicated slide
+      const newSlideNumber = slideIndex + 2; // +2 because we inserted after and slide numbers are 1-based
+      navigate(`/presentations/${presentationId}/edit/slides/${newSlideNumber}`);
       
     } catch (err) {
       console.error('Error duplicating slide:', err);
-      alert('Failed to duplicate slide');
+      setError(err instanceof Error ? err.message : 'Failed to duplicate slide');
     } finally {
       setSaving(false);
     }
@@ -106,20 +137,62 @@ export const PresentationEditor: React.FC = () => {
   const deleteSlide = async (slideIndex: number) => {
     if (!presentation) return;
     
-    if (!confirm('Are you sure you want to delete this slide?')) {
+    const slideToDelete = presentation.slides[slideIndex];
+    if (!slideToDelete) return;
+    
+    const slideNumber = slideIndex + 1;
+    const totalSlides = presentation.slides.length;
+    let confirmMessage = `Are you sure you want to delete slide ${slideNumber}?`;
+    
+    if (totalSlides === 1) {
+      confirmMessage = `Are you sure you want to delete the only slide in this presentation? The presentation will be empty after deletion.`;
+    } else {
+      confirmMessage += ` This will remove the slide and renumber all subsequent slides. This action cannot be undone.`;
+    }
+    
+    if (!confirm(confirmMessage)) {
       return;
     }
     
     try {
       setSaving(true);
+      setError(null);
       
-      // TODO: Implement slide deletion
-      console.log('Delete slide functionality to be implemented');
-      alert('Slide deletion will be implemented next.');
+      // Create updated presentation with the slide removed
+      const updatedPresentation = { ...presentation };
+      updatedPresentation.slides = presentation.slides.filter((_, index) => index !== slideIndex);
+      
+      // Update slide order for remaining slides
+      updatedPresentation.slides.forEach((slide, index) => {
+        slide.order = index;
+      });
+      
+      // Save the updated presentation
+      await updatePresentation(updatedPresentation);
+      
+      // Update local state
+      setPresentation(updatedPresentation);
+      
+      // Handle navigation after deletion
+      const totalSlides = updatedPresentation.slides.length;
+      if (totalSlides === 0) {
+        // No slides left, stay on editor main view
+        navigate(`/presentations/${presentationId}/edit`);
+      } else {
+        // Navigate to appropriate slide
+        let newSlideIndex = slideIndex;
+        if (slideIndex >= totalSlides) {
+          // If we deleted the last slide, go to the new last slide
+          newSlideIndex = totalSlides - 1;
+        }
+        // Navigate to the adjusted slide number
+        const slideNumber = newSlideIndex + 1;
+        navigate(`/presentations/${presentationId}/edit/slides/${slideNumber}`);
+      }
       
     } catch (err) {
       console.error('Error deleting slide:', err);
-      alert('Failed to delete slide');
+      setError(err instanceof Error ? err.message : 'Failed to delete slide');
     } finally {
       setSaving(false);
     }