Add 'detailing' activity state derived from active detail agents
(mode=detail, status running/waiting_for_input). Initiative cards show
pulsing "Detailing" indicator. Phase sidebar items show spinner during
active detailing and "Review changes" when the agent finishes.
listInitiatives now returns an activity object (state, activePhase, phase
counts) derived server-side from phases, eliminating per-card listPhases
queries. Initiative cards show a StatusDot with pulse animation + label
instead of a static StatusBadge. Removed redundant View and Spawn Architect
buttons from cards. Added variant override prop to StatusDot.