Concurrent subagent dispatch: `additionalDirectories` glob doesn't propagate from parent to child

Summary

When a parent agent dispatches a subagent (via the Agent / Task tool), the child subagent's permission resolver does not consistently honor glob-based entries in the parent's additionalDirectories. The child gets denied (or re-prompted) on paths that the parent has explicit permission to read via its own additionalDirectories globs.

Setup

• Claude Code CLI running with .claude/settings.json + .claude/settings.local.json
• Parent session has additionalDirectories: ["/repo/worktrees/*/.claude/features", "/repo/worktrees/*/.claude/shared"] (glob entries)
• Parent successfully reads files matching those globs
• Parent dispatches a child subagent with a prompt that asks the child to read a file matching the same glob

Expected

Child can read the file without prompting — it's within the parent's declared additionalDirectories surface.

Actual

Child is denied or prompted on first read, as if the glob entries weren't honored.

Reproducer

Minimal reproducer harness: https://github.com/Regevba/FitTracker2/tree/main/docs/superpowers/plans/f6-f9-reproducer (see child-agent-task-template.md § F6 and classification-template.md § F6).

Why we think it's not a config issue

We added the worktree glob entries to settings.local.json in wave-2 of a stress test. The wave still failed with per-child permission denials, ruling out the "missing declaration" hypothesis. See the "Framework Bug Saga" section of our post-stress-test case study for the full timeline.

Related

Possibly related to F7 (Edit/Write re-prompt) and F8 (parallel dispatch state drift) — filing separate issues in case the root causes differ; feel free to consolidate at triage if they're the same bug.

Workaround

Serial dispatch works fine. We've pivoted our remediation program (183/185 findings closed across 30+ PRs) to serial execution. Parallel dispatch has been blocked since 2026-04-18.