Update documentation to reflect recent frontend fixes and changes

Add notes on fixes for progress bar, async endpoint usage, polling logic, and result fetching.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 064f791d-a5ee-4eab-ab49-cbb215105dc0
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 811e65c5-a2c5-4a80-ad99-506d8804b0e0

.replit

@@ -4,7 +4,7 @@ expertMode = true
 
 [nix]
 channel = "stable-25_05"
-packages = ["freetype", "lcms2", "libimagequant", "libjpeg_turbo", "libpng", "libtiff", "libwebp", "libxcrypt", "tcl", "tk", "which", "zlib", "gut", "openssh_gssapi"]
+packages = ["freetype", "lcms2", "libimagequant", "libjpeg_turbo", "libpng", "libtiff", "libwebp", "libxcrypt", "tcl", "tk", "which", "zlib", "gut"]
 
 [workflows]
 runButton = "Project"

replit.md

@@ -92,6 +92,12 @@ Example response from progress endpoint:
 - **Background threading**: Server stays responsive during processing
 
 ## Recent Changes
+- 2025-11-28: Fixed frontend progress bar and image return issues
+  - Added visual progress bar with percentage display to frontend
+  - Updated frontend to use async endpoints for all features
+  - Added polling logic with proper error handling and timeouts
+  - Fixed image result fetching with 202 status handling
+  - All endpoints now show real-time progress during processing
 - 2025-11-28: Added progress tracking and async processing
   - New progress_tracker.py module with thread-safe job tracking
   - /progress/{job_id} and /result/{job_id} endpoints