Python Desktop App Developer – Merge Advanced PDF Sorting Logic & Script Automation into Existing UI

We have an existing, semi-integrated Python desktop automation application (v2.4.0) built with a modern dark-themed CustomTkinter (ctk) user interface. The app handles marketplace PDF label sorting and manipulation for e-commerce processing. We need an expert Python freelancer to cleanly pull advanced backend PDF processing algorithms from a legacy working version (v1 / pdf_extraction_v3.py), integrate them fully with our current CustomTkinter control buttons, and add compatibility for a separate, functional batch file (.bat) program designed to work alongside our legacy Amazon styling system. Key Objectives & Scope of Work Complete Backend Extraction & Integration (Amazon & Temu): Review our legacy source code file (pdf_extraction_v3.py) to extract the exact coordinate parameters, text-matching logic, PDF matrix splits, and multi-quantity repetition stamping functionality (*N). Bind these operational logic blocks step-by-step into the respective AmazonPanel and TemuPanel classes inside our newly formatted CustomTkinter layout script (main.py). Ensure that the data flows cleanly from the file browse rows into the active operational threads without causing UI lockups or freezing. External .bat Tool Integration (Amazon Workflow): The project requires integrating a separate, existing automation utility managed via a Windows Batch file (.bat). This batch program is known to work flawlessly with our legacy Amazon styling structures. You will modify the Amazon processing workflow within main.py to trigger/call this .bat script programmatically (using Python's subprocess module) as part of the pipeline run or expose an alternative control option to let it execute its automation sequence alongside the processed output files. Strict Boundary Rules (Etsy Component): CRITICAL REQUIREMENT: There is an existing Etsy Panel and sorting workflow inside main.py that is already fully configured, tested, and working perfectly. Do NOT alter, refactor, change, or move any line of code inside the EtsyPanel configuration or its corresponding backend functions (do_etsy_sort, label identification routines, etc.). Error Handling & Multi-Threading Optimization: Ensure all background tasks are fully isolated inside independent daemon threads (threading.Thread) so the graphical user interface stays responsive during large multi-page PDF processing operations. Implement strong local try-except blocks that pipe exceptions straight down to our visible, on-screen scrolledtext log areas to avoid silent terminal crashes. Technical Stack Required Python 3.9+ (Environment tested through Python 3.14) CustomTkinter (GUI Development Layouts) PyPDF2 / pypdf (Advanced PDF Metadata & Structural Extraction) ReportLab (Canvas coordinate geometry & dynamic page stamping overrides) Native Windows Shell Execution (Subprocess handling for .bat hooks)