Auto-spawned discuss/plan/refine agents were invisible because:
1. listInitiatives only filtered for mode='detail' agents
2. deriveInitiativeActivity returned 'idle' for zero phases before
checking for active agents
Broadened agent filter to all architect modes (discuss, plan, detail,
refine), moved active agent check before zero-phases early return, and
added 'discussing'/'refining' activity states with pulsing indicators.
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.
