Subagent agent name is not persisted, so nested subagents lose inherited permission restrictions #30610

Description

When the task tool creates a subagent session it does not store the agent name on the new session row. If that subagent spawns its own subagent, the permission resolver reads parent.agent to inherit the parent's restrictions, finds it empty, and drops the parent agent's edit denies on the grandchild.

The practical effect: a Plan-mode subagent that spawns another subagent ends up with a grandchild that can edit files, even though Plan mode forbids edits.

This is a different root cause from #30527, which is about prompt-time setPermission replacing instead of merging the ruleset. Here the agent column is never written at session creation, so deriveSubagentSessionPermission has nothing to read. Same code area as #26597, #26700, and #26747.

I have a fix that sets the agent name when the subagent session is created.

Plugins

None

OpenCode version

1.15.13

Steps to reproduce

1. Use an agent whose permissions deny edits (for example Plan mode).
2. Have it spawn a subagent via the task tool, and have that subagent spawn another subagent.
3. The deepest subagent is allowed to edit, because the deny was not inherited.

Screenshot and/or share link

No response

Operating System

Linux 6.17.0-29-generic

Terminal

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