One of our partners flagged that they were seeing the wrong order of
events when running `review/start` with command exec approvals:
```
{"method":"item/commandExecution/requestApproval","id":0,"params":{"threadId":"019c0b6b-6a42-7c02-99c4-98c80e88ac27","turnId":"0","itemId":"0","reason":"`/bin/zsh -lc 'git show b7a92b4eacf262c575f26b1e1ed621a357642e55 --stat'` requires approval: Xcode-required approval: Require explicit user confirmation for all commands.","proposedExecpolicyAmendment":null}}

{"method":"item/started","params":{"item":{"type":"commandExecution","id":"call_AEjlbHqLYNM7kbU3N6uw1CNi","command":"/bin/zsh -lc 'git show b7a92b4eacf262c575f26b1e1ed621a357642e55 --stat'","cwd":"/Users/devingreen/Desktop/SampleProject","processId":null,"status":"inProgress","commandActions":[{"type":"unknown","command":"git show b7a92b4eacf262c575f26b1e1ed621a357642e55 --stat"}],"aggregatedOutput":null,"exitCode":null,"durationMs":null},"threadId":"019c0b6b-6a42-7c02-99c4-98c80e88ac27","turnId":"0"}}
```

**Key fix**: In the review sub‑agent delegate we were forwarding exec
(and patch) approvals using the parent turn id (`parent_ctx.sub_id`) as
the approval call_id. That made
`item/commandExecution/requestApproval.itemId` differ from the actual
`item/started` id. We now forward the sub‑agent’s `call_id` from the
approval event instead, so the approval item id matches the
commandExecution item id in review flows.

Here’s the expected event order for an inline `review/start` that
triggers an exec approval after this fix:
1. Response to review/start (JSON‑RPC response)
- Includes `turn` (status inProgress) and `review_thread_id` (same as
parent thread for inline).
2. `turn/started` notification
  - turnId is the review turn id (e.g., "0").
3. `item/started` → EnteredReviewMode
  - item.id == turnId, marks entry into review mode.
4. `item/started` → commandExecution
  - item.id == <call_id> (e.g., "review-call-1"), status: inProgress.
5. `item/commandExecution/requestApproval` request
  - JSON‑RPC request (not a notification).
  - params.itemId == <call_id> and params.turnId == turnId.
6. Client replies to approval request (Approved / Declined / etc).
7. If approved:
  - Optional `item/commandExecution/outputDelta` notifications.
  - `item/completed` → commandExecution with status and exitCode.
8. Review finishes:
  - `item/started` → ExitedReviewMode
  - `item/completed` → ExitedReviewMode
  - (Agent message items may also appear, depending on review output.)
9. `turn/completed` notification

The key being #4 and #5 are now in the proper order with the correct
item id.