[Bug] Mobile Remote Control lacks subagent monitoring, manual cancellation, and query visibility

**Bug Description**
Describe the bug
When using remote control via the Android app, there is full lack of control over subagent execution.

Specifically:

No Cancel/Stop Mechanism: I cannot manually stop subagents if they behave unexpectedly or loop endlessly.

No Cost/Budget Control: Uncontrolled subagent execution continues to drain paid credits and subscription limits without an option to force-stop them.

No Query Visibility: I cannot view the active prompt queries or responses in real-time on mobile to verify if the subagents are acting correctly.

Expected behavior
The Android remote control interface should provide parity with the main CLI/desktop view:

Real-time stream of active subagent queries and prompts.

An active "Stop / Cancel Subagent" button.

Auto-pause or hard cancellation when subagents exceed budget/subscription limits.

**Environment Info**
- Platform: linux
- Terminal: vscode
- Version: 2.1.263
- Feedback ID: ddcc6411-118b-48c9-9f7b-b29ef40829c3

**Errors**
```json
[]
```

Start by tracing the Android remote-control entry point and comparing it with the main CLI/desktop subagent view. Check how active queries, cancellation, and budget limits are surfaced; done means mobile users can view active subagent work, stop it manually, and receive the requested limit handling.

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