Update app.py

Add SUB/hamb_echo

update to newest manifest with fixed BNL and BCUL data

Update app.py

Update app.py

New material and manifest

Enhance newspaper and provider alias handling

Update OCRQA exploration tool description and add demo link

add link to OCR QA Demo space

Enhance data handling and UI for OCRQA exploration tool

Add initial implementation of OCRQA exploration tool with data loading and visualization

initial commit