[STORY 7.1] Dynamic VCF Configuration Generator

[RamonRiosJr]

📝 Description

Move contact generation logic server-side handling intricate spec formatting to ensure frictionless import into native address books.

🎯 Acceptance Criteria

• Robust vCard 3.0 serialization adhering strictly to RFC 2426
• Base64 encoding pipeline converting uploaded R2 avatars into explicit PHOTO vCard parameters
• Return appropriate Content-Disposition: attachment mime-type mapped via Edge runtime functions