The Board view stops drawing a phase's members: the phase card stands for them there, and the columns go back to counting what you can see. Nothing is deleted, moved or marked — a member keeps its stage, its file, its agent and its actions.
heldByPhase()/columnCards()/columnNote() in board.html: the count is the length of the list drawn, and '+2 in phases' beside it says where the rest went, only where members are actually hidden. Membership is the only thing that hides a card, so removing it is the un-hiding: an archived phase card and an edited '## Cards' list stop deriving it, and a phase in done/ holds nothing. A card wearing phase drift is never hidden. The phase card carries the summary it now owes: a '1 of 2 merged' chip opening its own sheet, the member in flight on its activity line, and a halt worn in --alarm. Only the Board hides; Sessions, Focus, the header's live chip and the tab title still see an agent working on a hidden member.
Covered by tests/test_phase_members_hidden.py — collect() reads a throwaway tasks/ tree and the page's own rules run over that reading in node, plus source-level wiring invariants. Full suite green.
istos
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