feat: Replace initiative card N+1 queries with server-computed activity indicator

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.

docs/frontend.md

@@ -59,6 +59,7 @@ The initiative detail page has three tabs managed via local state (not URL param
 ### Core Components (`src/components/`)
 | Component | Purpose |
 |-----------|---------|
+| `InitiativeCard` | Initiative list card with activity indicator (dot + label + phase progress), overflow menu |
 | `InitiativeHeader` | Initiative name, project badges, inline-editable execution mode & branch |
 | `InitiativeContent` | Content tab with page tree + editor |
 | `StatusDot` | Small colored dot using status tokens, with pulse animation |
@@ -172,4 +173,11 @@ Configured in `src/lib/trpc.ts`. Uses `@trpc/react-query` with TanStack Query fo
 `packages/shared/` exports:
 - `sortByPriorityAndQueueTime()` — priority-based task sorting
 - `topologicalSort()` / `groupByPipelineColumn()` — phase DAG layout
+- `InitiativeActivity` / `InitiativeActivityState` — server-computed activity state for initiative cards
 - Shared type re-exports from `packages/shared/src/types.ts` (which re-exports from `apps/server/`)
+
+## Initiative Activity Indicator
+
+`listInitiatives` returns an `activity` field on each initiative, computed server-side from phase statuses via `deriveInitiativeActivity()` in `apps/server/trpc/routers/initiative-activity.ts`. This eliminates per-card N+1 `listPhases` queries.
+
+Activity states (priority order): `pending_review` > `executing` > `blocked` > `complete` > `ready` > `planning` > `idle` > `archived`. Each state maps to a `StatusVariant` + pulse animation in `InitiativeCard`'s `activityVisual()` function.