Normalize all Python sources to the standard ADN copyright block with
complete GPLv3 notice. Add legacy attribution on routing and dmr_utils
ports; drop SemVer wording from changelog and fix an unused test import.
Replace internal bridge terminology with routing (RoutingUseCases, AclRouter,
routing_table export). SubscriptionStore remains runtime authority with O(1)
indexes for router and downlink filters. Fix STATIC TG parity on OPTIONS/RPTO,
parrot in-band edge cases, and remove per-packet routing_table export from the
hot path that caused high CPU under multi-hotspot OBP load.
Rodrigo Pérez