/compact on the main session aborts running subagents #307

What happened?

Sending /compact in the main session while a subagent is still working aborts the subagent instead of only compacting the main context.

Observed order in the session:

1. ✗ subagent review → Subagent was aborted · 可回复「重试」让模型换一种方式，或补充说明预期结果
2. Error: The operation was aborted.
3. Compaction · Compacted from 225,250 tokens

The child session is torn down first, and compaction only finishes afterwards. The subagent's partial work and its final report are lost, so the task had to be re-dispatched from scratch.

Steps to reproduce

1. Ask the main agent to do work that spawns a subagent (e.g. a long review task) and wait until the subagent is actively running.
2. While it is still running, send /compact in the main session.
3. The subagent is aborted immediately with Error: The operation was aborted., then compaction runs.

Expected behavior

/compact should only rewrite the main session's context. A running subagent lives in its own child session and should keep running unaffected — or at least be cancelled explicitly, not silently aborted as a side effect of compacting the parent.

Version

0.1.6 (Windows 11, 10.0.26300)