[deploy] #9 Network-wide shadow mode

[vxfemboy]

M0 (#166). A global 'log what I would blackhole/FlowSpec, act on nothing' across both planes; diff intended-vs-actual before arming.
Status: NONE · Size: M · Home: blackwall-rtbh/flowspec/xdp controllers.
Pro: THE interlock that makes it safe to run a mid-dev daemon on the security boundary. Con: a first-class flag threaded through the controllers. Needs its own spec→plan.

[vxfemboy]

Shipped via PR #187 (global shadow mode: RTBH/FlowSpec/XDP logged+recorded, not applied).