fix(opencode): cascade auto permissions to subagent sessions

[vladislav-miroshnikov]

Issue for this PR

Fixes #41730

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

When opencode run spawns a subagent, permission requests belong to the child session. Filtering only for the root session leaves that subagent waiting forever.

The run event loop now accepts permission requests from the attached root session and sessions whose parentID chain reaches that root. Proven descendants are cached. Requests from unrelated sessions in the same workspace remain untouched, so --auto cannot approve another concurrent session's request.

How did you verify your code works?

• cd packages/opencode && bun test test/cli/run/run-process.test.ts — 16 pass, 0 fail
• cd packages/opencode && bun test test/permission-task.test.ts — 21 pass, 0 fail
• cd packages/opencode && bun typecheck

The subprocess matrix covers child auto-approval, child auto-rejection without --auto, and an attach-mode negative case proving an unrelated session's pending permission is not answered.

Checklist

• I have read the contributing guide
• I have verified my code works on the target platform

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Based on my search results, I found one potentially related PR:

#37902 - fix(acp): child/subagent session permission requests no longer hang forever

This PR appears to address a similar issue with child/subagent session permission requests hanging. It may be related to or a predecessor of the current PR's fix for cascading auto permissions to subagent sessions.

[vladislav-miroshnikov]

@rekram1-node Updated on f69becea, keeping #43675's event tracking and checking the saved parent chain only on a cache miss. The new two-process test reuses an already saved child: it times out without the fallback and passes with it. The unrelated-session control, package typecheck and formatting pass too. Could you review this remaining resumed-child case?