closes #487

Summary

This PR implements a comprehensive client-side Task Management system for Image Optimization in the Form Validation library. It resolves performance issues and UI freezing during batch image uploads by introducing a concurrency-limited task queue, status/progress tracking, and cancellation capabilities.

Changes Made

1. ImageOptimizationTaskManager (src/form-management/validation/image-optimization-task-manager.ts) [NEW]:
   • Introduced a task manager handling FIFO scheduling, concurrency limit constraints (maxConcurrentTasks), state tracking (pending, processing, completed, failed, cancelled), and events callback subscriptions.
   • Provided standard Promise-based APIs (waitForTask and waitForAll) to await task completion.
   • Implemented individual task cancellation and bulk cancellation (cancelAll).
2. optimizeImage (src/form-management/validation/image-optimizer.ts):
   • Added an optional onProgress callback to ImageOptimizationOptions.
   • Propagated progress callbacks during file reading (30%), image load (60%), and canvas toBlob generation (100%).
3. ValidationEngineImpl (src/form-management/validation/validation-engine.ts):
   • Integrated the ImageOptimizationTaskManager instance into the validation engine.
   • Updated the validateImageOptimize rule runner to enqueue and wait for optimization tasks via the task manager.
4. index.ts (src/form-management/validation/index.ts):
   • Exported ImageOptimizationTaskManager and its related types.
5. image-optimization.md (src/form-management/validation/image-optimization.md):
   • Updated features list and added a detailed usage guide for the task manager.

Testing & Verification

A new test suite image-optimization-task-manager.test.ts was created to verify all core task management functionalities:

• Concurrency limit compliance.
• Status/progress transition callback triggers.
• Task cancellation behavior (pending vs processing).
• Promise resolution/rejections.
• Error handling on execution failures.