feat(orchestration-v2): populate subagent observability from providers

Fills in the data model added by the previous PR. Every adapter now
reports what its subagents are actually doing: role provenance, token
usage, recent activity, and per-activation records.

Usage needs two merge strategies because providers report it
differently. Codex sends cumulative snapshots per thread, so those merge
by maximum — duplicate and late out-of-order frames then leave the total
unchanged instead of inflating it. Claude reports per activation, so
lifetime usage accumulates only the delta since the previous snapshot.

A subagent identity is reusable, so completing an activation leaves it
at "idle" rather than "completed"; the timeline row for that activation
is still recorded as completed via the status mapping.

Three activation-lifecycle fixes in the Claude adapter, found in review:

- A resume that raced past settle was pre-opened by the wake buffer,
  which erased the terminal status the reopen check reads. The resume
  then reused the finished activation instead of starting a new one, so
  its ordinal stopped matching reality and its usage was measured
  against the previous activation's totals — clamping the delta to zero
  and silently dropping the resumed run's tokens. The pre-open now
  records that it happened, and the reopen check honours it.
- A replayed "waiting" frame could resurrect a settled subagent; only
  pending/running were guarded before.
- A duplicate terminal frame re-stamped completedAt, drifting the
  recorded completion time. Codex already preserved it; Claude now
  matches.

Reuse across runs is deliberately not addressed here — a subagent row
still carries the run it was spawned under. That is the next PR.

Author: shivamhwp

apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.ts

@@ -12,6 +12,7 @@ import {
   type OrchestrationV2ProviderTurn,
   type OrchestrationV2RuntimeRequest,
   type OrchestrationV2Subagent,
+  type OrchestrationV2SubagentActivation,
   type OrchestrationV2TurnItem,
   type OrchestrationV2UserInputQuestion,
   type ProviderApprovalDecision,
@@ -66,6 +67,7 @@ import {
   makeSubagentConversationArtifacts,
   subagentThreadTitle,
 } from "../SubagentProjection.ts";
+import { defaultSubagentRole, subagentActivationId } from "../SubagentObservability.ts";
 import {
   ProviderAdapterEnsureThreadError,
   ProviderAdapterForkThreadError,
@@ -1926,6 +1928,12 @@ export function makeAcpAdapterV2(options: AcpAdapterV2Options): ProviderAdapterV
           const turnItemOrdinal =
             existing?.turnItemOrdinal ?? (yield* resolveItemOrdinal(context, nativeTaskId));
           const taskStatus = update.status;
+          const activationId = subagentActivationId(nodeId, 1);
+          const settled =
+            taskStatus === "completed" ||
+            taskStatus === "failed" ||
+            taskStatus === "cancelled" ||
+            taskStatus === "interrupted";
           const task: OrchestrationV2Subagent = {
             ...(existing?.task ?? {
               id: nodeId,
@@ -1942,20 +1950,21 @@ export function makeAcpAdapterV2(options: AcpAdapterV2Options): ProviderAdapterV
               prompt: update.prompt,
               title: update.title,
               model: update.model,
-              kind: "subagent",
-              role: { name: "general-purpose", source: "app_default" },
+              kind: "subagent" as const,
+              role: defaultSubagentRole(),
+              result: null,
               usage: null,
-              currentActivationId: null,
+              currentActivationId: activationId,
               activationCount: 1,
               workflow: null,
               workflowMembership: null,
               recentActivity: [],
-              result: null,
               startedAt: now,
             }),
             status: taskStatus,
             result: existing?.assistantText || update.result,
-            completedAt: taskStatus === "running" ? null : now,
+            currentActivationId: settled ? null : activationId,
+            completedAt: settled ? (existing?.task.completedAt ?? now) : null,
             updatedAt: now,
           };
           const subagent: ActiveAcpSubagent = existing ?? {
@@ -2073,7 +2082,7 @@ export function makeAcpAdapterV2(options: AcpAdapterV2Options): ProviderAdapterV
             ...subagent.task,
             status: taskStatus,
             result,
-            completedAt: taskStatus === "running" ? null : now,
+            completedAt: settled ? (subagent.task.completedAt ?? now) : null,
             updatedAt: now,
           };
           const providerThreadId = subagent.task.providerThreadId;
@@ -2120,6 +2129,23 @@ export function makeAcpAdapterV2(options: AcpAdapterV2Options): ProviderAdapterV
             },
           });
           yield* emitProviderEvent({ type: "subagent.updated", driver, subagent: subagent.task });
+          yield* emitProviderEvent({
+            type: "subagent_activation.updated",
+            driver,
+            activation: {
+              id: activationId,
+              threadId: subagent.task.threadId,
+              subagentId: subagent.task.id,
+              runId: subagent.task.runId,
+              providerTurnId: subagent.providerTurnId,
+              ordinal: 1,
+              status: taskStatus,
+              usage: null,
+              startedAt: subagent.task.startedAt,
+              completedAt: settled ? now : null,
+              updatedAt: now,
+            } satisfies OrchestrationV2SubagentActivation,
+          });
           yield* emitProviderEvent({
             type: "turn_item.updated",
             driver,