feat(agent): budget reminders, usage while waiting, budget-exceeded status and dedupe

- tool results carry a budget reminder near limits; text before the last tool
  call is dropped as report when cut by budget/abort
- usage persisted when a run suspends, so waiting sessions show spent tokens
- task page shows budget_exceeded via business.outcome instead of completed
- budget-exceeded decisions merge by root cause (decision / schedule / goal
  template); new summaries added to investigate allowlist

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/test/system/system.test.ts

@@ -427,7 +427,14 @@ describe.skipIf(!hasPg)("W9-I 进程与健康(真实 PG)", () => {
     const list = await json(await admin("GET", "/engine/runs?from=2026-09-10T00:00:00Z&to=2026-09-11T00:00:00Z"));
     const by = new Map(list.data.items.map((r: { id: string; business: unknown }) => [r.id, r.business]));
     expect(by.get("b1")).toEqual({ kind: "feed", refId: feedId, title: "HDSky RSS", triggeredBy: "event" });
-    expect(by.get("b2")).toEqual({ kind: "agent", refId: agentId, title: "巡检:待处理", triggeredBy: "schedule" });
+    expect(by.get("b2")).toEqual({
+      kind: "agent",
+      refId: agentId,
+      title: "巡检:待处理",
+      triggeredBy: "schedule",
+      // AG-3:Agent 会话带业务结果(任务页据此显示超出预算 / 失败,而不是引擎的「完成」)
+      outcome: "queued",
+    });
     expect(by.get("b3")).toEqual({
       kind: "organization",
       refId: "00000000-0000-0000-0000-0000000000aa",