feat: map Privacy messaging, VPN, and footprint onto the Security Map

Seed default E2EE chat, VPN on untrusted networks, and digital-footprint
reduction. Data-removal, financial privacy, privacy OS, and VPN provider
catalogs stay unmapped. A VPN is not HTTPS. Discord is not E2EE.
Cross-links to Encryption, OpSec, Community, and Physical Security come
from shared devices, TLS, channels, and identity separation.

Author: mattaereal