Bug: Plan approval in autopilot+fleet mode triggers execution with fleet dispatch ordering mismatch

## Description

When approving a plan in plan mode while using autopilot+fleet, the plan approval immediately triggers execution AND fleet agent dispatch simultaneously. The "Queued (1)" and "Fleet deployed" messages appear while the main agent is still "Analyzing bugs and planning fixes," suggesting a sequencing/ordering issue between the main agent's work and fleet dispatch.

## Steps to Reproduce

1. Enter plan mode and create a plan (e.g., with multiple bugs/features)
2. Switch to autopilot+fleet mode
3. Copilot recommends committing to the plan with autopilot+fleet
4. Approve/select that recommendation

## Expected Behavior

Plan approval should properly sequence execution — the main agent's analysis should be coordinated with fleet agent dispatch, not race against it.

## Actual Behavior

Fleet dispatch ("Queued (1)", "Fleet deployed") fires concurrently with the main agent beginning its "Analyzing bugs and planning fixes" phase. This ordering mismatch suggests the fleet agents are dispatched before the main agent has finished planning/coordinating the work.

## Screenshot

*(Screenshot shows: Plan approved -> "Analyzing bugs and planning fixes" starts -> "Queued (1)" / "Fleet deployed" messages appear simultaneously)*

## Environment

- OS: Windows
- Copilot CLI version: latest (as of April 2026)
- Mode: Autopilot + Fleet (experimental)

## Additional Context

Also submitted private feedback via the `/feedback` command for internal tracking.

まず Windows autopilot+fleet mode でプラン承認フローを再現し、承認からメインエージェントの計画フェーズおよびフリートディスパッチへの遷移を追跡します。これらの操作の順序を比較し、ディスパッチがどこでトリガーされるかを特定します。完了の条件は、フリートのデプロイがメインエージェントの計画と連携して行われ、同時並行で実行されず、報告されるステータスメッセージが正しい順序で表示されることです。

索引モデルが issue の本文から書いたものです。