AGGRESSIVE FORCE REBUILD: Multiple file changes to trigger HF rebuild

Implement improved spell checking system with regex, domain allowlist, and confidence filtering

Add PyMuPDF fallback and comprehensive poppler packages for PDF processing

Fix Space initialization: add launch() and update gradio version

Setup HF Space: Gradio app, deps (gradio), apt packages

Increase PDF resolution: DPI from 300 to 600, scaling factors improved for better OCR and barcode detection