PyPDF2 missing from requirements.txt causes ImportError

[Four-af]

Bug Description

pdf_input_validator.py imports PyPDF2 but requirements.txt only lists three packages (streamlit, google-generativeai, fpdf2). Running pip install -r requirements.txt followed by any code path that triggers PDF validation raises ModuleNotFoundError: No module named 'PyPDF2'.

Steps to Reproduce

1. pip install -r requirements.txt
2. Trigger PDF validation in the app

Expected Behaviour

PDF validation works without needing manual extra installs.

Proposed Fix

Add PyPDF2 to requirements.txt.

Labels: bug, good first issue