feat(02-02): add council orchestrator and result collector

- Implement executeCouncil with parallel member launch and partial-failure tolerance

- Add result collection mapping and wire Athena exports with read-only athena tool restrictions

src/agents/athena/council-result-collector.ts

@@ -0,0 +1,36 @@
+import type { BackgroundTask, BackgroundTaskStatus } from "../../features/background-agent/types"
+import type { CouncilMemberConfig, CouncilMemberResponse, CouncilMemberStatus } from "./types"
+
+export function collectCouncilResults(
+  tasks: BackgroundTask[],
+  members: CouncilMemberConfig[],
+  startTimes: Map<string, number>
+): CouncilMemberResponse[] {
+  return tasks.map((task, index) => {
+    const member = members[index]
+    const status = mapTaskStatus(task.status)
+    const startTime = startTimes.get(task.id) ?? Date.now()
+    const finishedAt = task.completedAt?.getTime() ?? Date.now()
+
+    return {
+      member,
+      status,
+      response: status === "completed" ? task.result : undefined,
+      error: status === "completed" ? undefined : (task.error ?? `Task status: ${task.status}`),
+      taskId: task.id,
+      durationMs: Math.max(0, finishedAt - startTime),
+    }
+  })
+}
+
+function mapTaskStatus(taskStatus: BackgroundTaskStatus): CouncilMemberStatus {
+  if (taskStatus === "completed") {
+    return "completed"
+  }
+
+  if (taskStatus === "cancelled" || taskStatus === "interrupt") {
+    return "timeout"
+  }
+
+  return "error"
+}