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/e2e/e12-interaction.test.ts

@@ -229,6 +229,8 @@ describe.skipIf(!hasPg)("E12 Agent 交互:步骤清单 / 方案选择 / 内联
       "挂起等待方案",
     );
     expect(waiting.summary).toBe("等待选择方案");
+    // AG-3:挂起时没有 run_completed,已用累计照样写回(等待期间界面显示已用 token / 费用,而不是"未报告")
+    expect(Number((waiting.usage as Any).totalTokens ?? 0)).toBeGreaterThan(0);
     const decision = await e.db
       .selectFrom("decision")
       .selectAll()