...Watermark images (9 algorithms), audio (8) and documents (5); compute 21 fingerprint hashes; sign and verify C2PA provenance; issue Ed25519/P-256/RSA DID keys; generate PDF/DOCX/EPUB certificates; forensic ELA/noise/JPEG-marker analysis. Vanilla JS, no framework, runs fully client-side. Not a full PDF editor - watermarking, provenance and verification only.