Add SHA-3 hash reporting support

[Zsh123456-BOOP]

/claim #2

Summary

• add SHA-3-256 (Keccak) hashing alongside the existing MD5 and SHA-256 calculations
• show SHA-3-256 in the main hash table and include it in CSV, Excel, PDF, Word, and email PDF reports
• log SHA-3-256 calculation completion in the browser console for lightweight verification

Validation

• node --check on the extracted inline script from index.html
• git diff --check
• Chrome headless smoke test using an injected abc.txt file, verifying MD5/SHA-256/SHA-3-256 outputs and the Excel export button