Remove failed CI card image generation feature and document lessons learned

- Revert .github/workflows/test.yml to simple lint/build/test workflow
- Remove Tests/PlayingCardTests/DisplayCardSnapshotTests.swift (entire file)
- Remove .github/workflows/cleanup-card-images.yml
- Clean up .gitignore to remove card-images/ entries
- Add comprehensive "FAILED APPROACHES" section to AGENTS.md documenting:
  * Technical failures of SwiftUI rendering in headless CI
  * Test discovery issues with conditional compilation
  * Complex fallback logic problems
  * Lessons for future attempts

Co-authored-by: infomofo <539599+infomofo@users.noreply.github.com>

Author: Copilot

.github/workflows/cleanup-card-images.yml

@@ -6,11 +6,6 @@ on:
   pull_request:
     branches: [ "main" ]
 
-permissions:
-  contents: read
-  pull-requests: write
-  issues: write
-
 jobs:
   test:
     runs-on: macos-latest
@@ -30,170 +25,3 @@ jobs:
 
       - name: Run tests
         run: make test
-      
-      - name: Generate sample card images
-        run: |
-          echo "🔍 Current working directory: $(pwd)"
-          echo "🧪 Running image generation test..."
-          swift test --filter PlayingCardTests.DisplayCardSnapshotTests.testGenerateSampleCardImages
-        
-      - name: Check for generated images
-        run: |
-          echo "Checking for card images directory..."
-          if [ -d "card-images" ]; then
-            echo "✅ card-images directory exists"
-            echo "Contents:"
-            ls -la card-images/
-          else
-            echo "❌ card-images directory not found"
-            echo "Current directory contents:"
-            ls -la
-          fi
-          
-      - name: Commit card images to repository
-        if: always()
-        run: |
-          # Configure git for the action
-          git config --local user.email "action@github.com"
-          git config --local user.name "GitHub Action"
-          
-          # Create a temporary branch for images if it doesn't exist
-          if [ -d "card-images" ]; then
-            echo "📸 Committing generated card images..."
-            
-            # Add the images to git
-            git add card-images/
-            
-            # Only commit if there are changes
-            if ! git diff --cached --quiet; then
-              git commit -m "Add generated card images for PR review [skip ci]"
-              git push origin HEAD
-              echo "✅ Images committed and pushed"
-            else
-              echo "ℹ️ No new images to commit"
-            fi
-          else
-            echo "⚠️ No card-images directory found to commit"
-          fi
-          
-      - name: Upload card images as artifacts
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: sample-card-images
-          path: card-images/
-          retention-days: 30
-          
-      - name: Comment PR with embedded card images
-        if: github.event_name == 'pull_request' && always()
-        uses: actions/github-script@v7
-        with:
-          script: |
-            const fs = require('fs');
-            
-            console.log('🔍 Starting PR comment generation...');
-            
-            // Check if card images directory exists
-            const cardImagesDir = 'card-images';
-            if (!fs.existsSync(cardImagesDir)) {
-              console.log('❌ No card images directory found');
-              await github.rest.issues.createComment({
-                issue_number: context.issue.number,
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                body: `## ⚠️ Card Image Generation Failed\n\nThe workflow was unable to generate sample playing card images. This indicates an issue with the test execution.\n\n**Debug Info**: Generated at ${new Date().toISOString()}`
-              });
-              return;
-            }
-            
-            console.log('✅ Found card-images directory');
-            
-            // Get list of generated files
-            const allFiles = fs.readdirSync(cardImagesDir).sort();
-            const imageFiles = allFiles.filter(file => file.endsWith('.png'));
-            
-            console.log(`🖼️ Found ${imageFiles.length} PNG files: ${imageFiles.join(', ')}`);
-            
-            // Read manifest for card information
-            let cardList = [];
-            const manifestFile = 'manifest.txt';
-            if (allFiles.includes(manifestFile)) {
-              const manifestPath = `${cardImagesDir}/${manifestFile}`;
-              const manifestContent = fs.readFileSync(manifestPath, 'utf8');
-              cardList = manifestContent.trim().split('\n').filter(line => line.trim());
-              console.log(`📝 Manifest contains ${cardList.length} cards: ${cardList.join(', ')}`);
-            }
-            
-            // Create comment body
-            let commentBody = `## 🃏 Sample Playing Cards Generated\n\n`;
-            commentBody += `The following sample cards were generated from the \`DisplayCard\` SwiftUI component:\n\n`;
-            
-            const suitEmojis = {
-              'spades': '♠️',
-              'hearts': '♥️', 
-              'diamonds': '♦️',
-              'clubs': '♣️'
-            };
-            
-            // Get the current branch name for image URLs
-            const currentBranch = context.ref.replace('refs/heads/', '');
-            const repoUrl = `https://github.com/${context.repo.owner}/${context.repo.repo}`;
-            
-            if (cardList.length > 0 && imageFiles.length > 0) {
-              // Create mapping from card description to image filename
-              const cardImageMap = new Map();
-              cardList.forEach(cardInfo => {
-                const parts = cardInfo.split(' of ');
-                if (parts.length === 2) {
-                  const rank = parts[0].toLowerCase();
-                  const suit = parts[1].toLowerCase();
-                  const expectedFilename = `${suit}_${rank}.png`;
-                  if (imageFiles.includes(expectedFilename)) {
-                    cardImageMap.set(cardInfo, expectedFilename);
-                  }
-                }
-              });
-              
-              // Embed actual images
-              for (const cardInfo of cardList) {
-                // Add appropriate emoji based on suit
-                let displayName = cardInfo;
-                for (const [suit, emoji] of Object.entries(suitEmojis)) {
-                  if (cardInfo.toLowerCase().includes(suit)) {
-                    displayName = `${cardInfo} ${emoji}`;
-                    break;
-                  }
-                }
-                
-                const imageFilename = cardImageMap.get(cardInfo);
-                if (imageFilename) {
-                  // Embed the image using GitHub's raw content URL
-                  const imageUrl = `${repoUrl}/raw/${currentBranch}/card-images/${imageFilename}`;
-                  commentBody += `### ${displayName}\n`;
-                  commentBody += `![${cardInfo}](${imageUrl})\n\n`;
-                } else {
-                  commentBody += `### ${displayName}\n`;
-                  commentBody += `*Image generation failed for this card*\n\n`;
-                }
-              }
-              
-              commentBody += `\n**Format**: ${imageFiles.length} PNG image(s) generated from SwiftUI DisplayCard component\n`;
-            } else {
-              commentBody += `Card generation completed but no valid cards were found.\n\n`;
-            }
-            
-            commentBody += `\n📁 **Artifacts**: The generated files are also available as artifacts in the [Actions tab](${context.payload.repository.html_url}/actions/runs/${context.runId}).\n\n`;
-            commentBody += `These help reviewers visualize how the \`DisplayCard\` SwiftUI component renders different playing cards.\n\n`;
-            commentBody += `**Generated**: ${allFiles.length} file(s) at ${new Date().toISOString()}`;
-            
-            console.log('💬 Posting PR comment with embedded images...');
-            
-            // Post comment on PR
-            await github.rest.issues.createComment({
-              issue_number: context.issue.number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: commentBody
-            });
-            
-            console.log('✅ Successfully posted PR comment with embedded card images');

.github/workflows/test.yml

@@ -10,8 +10,5 @@
 # Generated test images (uploaded as CI artifacts instead)
 Tests/PlayingCardTests/*.png
 
-# Generated card images from snapshot tests (temporarily committed for PR comments)
-# card-images/
-
 # SwiftLint temporary files
 .swiftlint_output

.gitignore

@@ -198,6 +198,44 @@ Example of the transformation:
 3. Simplify GitHub Actions workflows to remove complex detection logic
 4. Focus on the user's actual need (images in PR comments) rather than perfect technical implementation
    - Use GitHub's file URLs: `https://github.com/owner/repo/raw/branch/path/to/image.png`
+
+## ⚠️ FAILED APPROACHES - DO NOT REPEAT
+
+### Card Image Generation in CI (August 2025)
+
+**FAILED FEATURE**: Automated card image generation with PR comment embedding
+
+**What was attempted**: A CI workflow that would generate sample playing card images during PR builds and embed them in PR comments to help reviewers visualize card rendering.
+
+**Why it failed repeatedly**:
+1. **Test discovery inconsistency**: `#if canImport(SwiftUI)` conditional compilation meant tests didn't exist on some platforms, causing `swift test --filter` to succeed with 0 tests executed
+2. **SwiftUI rendering fragility**: Even on macOS CI runners, SwiftUI-to-image conversion (NSHostingView, SwiftUI.ImageRenderer) failed silently in headless environments
+3. **Complex fallback logic**: Multiple layers of fallback detection in GitHub Actions YAML became unmaintainable and introduced their own failure points
+4. **Iteration difficulty**: Agent couldn't predict failure scenarios, leading to 15+ commits of back-and-forth fixes without resolution
+
+**Specific technical failures**:
+- NSHostingView couldn't create valid NSImage from SwiftUI views in headless CI
+- SwiftUI.ImageRenderer with @MainActor annotation still failed to render
+- GitHub Actions `||` fallback syntax was unreliable with proper exit code handling
+- Test filter patterns failed when tests were conditionally compiled out
+- Complex PNG generation fallbacks created invalid files that broke subsequent workflow steps
+
+**Root cause**: **Over-engineering a simple problem**. The goal was just to show sample card images in PR comments, but the implementation became a complex system trying to handle every possible CI environment failure scenario.
+
+**Lesson for future attempts**:
+- **Don't attempt SwiftUI rendering in CI** - it's fundamentally unreliable in headless environments
+- **Don't use conditional compilation for CI-critical tests** - tests should exist on all platforms
+- **Start with the simplest possible solution** - static placeholder images may be better than complex rendering
+- **Test the CI scenario locally first** - but recognize that local testing may not catch all CI environment issues
+- **Have a clear "abort" criteria** - if something fails more than 3-4 iterations, the approach is likely fundamentally flawed
+
+**Alternative approaches to consider**:
+1. **Static sample images**: Pre-generated images committed to the repository
+2. **Manual image updates**: Developer-generated images updated when UI changes
+3. **Local-only image generation**: Developer runs script locally and commits results
+4. **Skip image generation entirely**: Focus on text-based PR descriptions of UI changes
+
+**DO NOT** attempt to resurrect this exact approach without fundamentally different technical strategy.
    - Add cleanup workflows to remove images after PR closure
    - Consider image file sizes to avoid repository bloat