Mechanical fixes: em dashes, typos, heading prefix, numbers, banned words, vpnTUN
Restore [!TYPE] callout format across all wiki pages
wiki crosswalk: convert all callouts to blockquote format, fix checkpoints, move AV warning to First Run
rename extVPN to vpnTUN: terminology, page 16, variable names, service name
make See Also sections non-collapsible and unified across wiki
make all ## sections collapsible across wiki
expand Deployment Mode Architecture into full primer + deep dive, move to page 03