Subagents don't inherit file permissions granted in parent session

Description

When a user grants permission to edit a file in the main session, subagents spawned via the Task tool don't inherit that permission. They prompt for the same permission again.

Steps to reproduce

1. Start a Claude Code session
2. Attempt to edit a file (e.g., skill.md)
3. Grant permission when prompted
4. Spawn a subagent (e.g., Plan agent) that needs to read/edit the same file
5. Subagent prompts for permission again, even though it was just granted seconds before

Expected behavior

Subagents should inherit permissions already granted in the parent session for the duration of that session.

Actual behavior

Each subagent requires separate permission grants for the same files, even when the parent session already has permission.

Environment

• Claude Code CLI
• Observed during plan mode with Task tool subagents