V2: Convert Tool (#3828)

🔄 Dynamic Processing Strategies

- Adaptive routing: Same tool uses different backend endpoints based on
file analysis
- Combined vs separate processing: Intelligently chooses between merge
operations and individual file processing
- Cross-format workflows: Enable complex conversions like "mixed files →
PDF" that other tools can't handle

  ⚙️ Format-Specific Intelligence

  Each conversion type gets tailored options:
  - HTML/ZIP → PDF: Zoom controls (0.1-3.0 increments) with live preview
  - Email → PDF: Attachment handling, size limits, recipient control
  - PDF → PDF/A: Digital signature detection with warnings
  - Images → PDF: Smart combining vs individual file options

 File Architecture

  Core Implementation:
  ├── Convert.tsx                     # Main stepped workflow UI
├── ConvertSettings.tsx # Centralized settings with smart detection
├── GroupedFormatDropdown.tsx # Enhanced format selector with grouping
├── useConvertParameters.ts # Smart detection & parameter management
  ├── useConvertOperation.ts         # Multi-strategy processing logic
  └── Settings Components:
      ├── ConvertFromWebSettings.tsx      # HTML zoom controls
      ├── ConvertFromEmailSettings.tsx    # Email attachment options
├── ConvertToPdfaSettings.tsx # PDF/A with signature detection
      ├── ConvertFromImageSettings.tsx    # Image PDF options
      └── ConvertToImageSettings.tsx      # PDF to image options

 Utility Layer

  Utils & Services:
├── convertUtils.ts # Format detection & endpoint routing
  ├── fileResponseUtils.ts          # Generic API response handling
└── setupTests.ts # Enhanced test environment with crypto mocks

  Testing & Quality

  Comprehensive Test Coverage

  Test Suite:
├── useConvertParameters.test.ts # Parameter logic & smart detection
  ├── useConvertParametersAutoDetection.test.ts  # File type analysis
├── ConvertIntegration.test.tsx # End-to-end conversion workflows
  ├── ConvertSmartDetectionIntegration.test.tsx  # Mixed file scenarios
  ├── ConvertE2E.spec.ts                     # Playwright browser tests
├── convertUtils.test.ts # Utility function validation
  └── fileResponseUtils.test.ts              # API response handling

  Advanced Test Features

  - Crypto API mocking: Proper test environment for file hashing
  - File.arrayBuffer() polyfills: Complete browser API simulation
  - Multi-file scenario testing: Complex batch processing validation
- CI/CD integration: Vitest runs in GitHub Actions with proper artifacts

---------

Co-authored-by: Connor Yoh <[email protected]>
Co-authored-by: Anthony Stirling <[email protected]>

frontend/src/utils/thumbnailUtils.ts

@@ -24,6 +24,11 @@ export async function generateThumbnailForFile(file: File): Promise<string | und
     console.log('Skipping thumbnail generation for large file:', file.name);
     return undefined;
   }
+
+  if (!file.type.startsWith('application/pdf')) {
+    console.warn('File is not a PDF, skipping thumbnail generation:', file.name);
+    return undefined;
+  }
   
   try {
     console.log('Generating thumbnail for', file.name);