Add EquipmentTagPlan + an init-only EquipmentTags member on Phase7CompositionResult
(mirror of GalaxyTags). Populate it compose-side (Tag.EquipmentId != null AND owning
namespace Kind == Equipment) and artifact-decode-side via BuildEquipmentTagPlans, with
FullName extracted from Tag.TagConfig. Init-only member (not a 7th positional param) so
existing convenience constructors + call sites are untouched.
Implements WS-1/WS-2/WS-4 (+ tests) of the materialization scope: carry
Equipment-namespace tags through the composition/artifact, add a sink-based
MaterialiseEquipmentTags pass to the live rebuild, browse folders by friendly
Name (NodeId stays the logical Id). 6 tasks with dependencies; structure-only
(BadWaitingForInitialData leaves) — live values are the next milestone. Resume
via /executing-plans docs/plans/2026-06-06-equipment-namespace-structure-milestone.md