[FEATURE] Cowork Dispatch: child task sessions should inherit parent's mounted directory

Feature Request

When Dispatch spawns child task sessions via start_task, each child session is completely isolated from the parent. If the parent Dispatch session has mounted a directory (via request_cowork_directory), child sessions cannot access it. Each child must call request_cowork_directory independently, which triggers a separate user permission prompt every time.

This makes autonomous multi-task workflows impractical. Spawning 3 parallel tasks means 3 separate permission popups for the same folder the parent already has access to.

Requested Behaviour

Child task sessions created by start_task should inherit the parent Dispatch session's mounted directories without requiring a separate user prompt. The user already granted access when they mounted the folder in the parent session. Child sessions should operate within that same trust boundary.

Why This Matters

Cowork's value proposition is autonomous task execution. Dispatch is designed to orchestrate multiple task sessions in parallel. But the permission model treats each child session as if it were a brand new conversation with an untrusted agent, even though the parent session (which the user is actively working in) already has access.

The result is that every start_task call that touches files requires the user to manually click "Allow" in the UI. For a workflow that spawns 3-5 tasks, that's 3-5 interruptions. If the user steps away (which is the whole point of autonomous operation), the tasks block indefinitely waiting for permission.

Current Workarounds

1. Do all work in the parent Dispatch session (eliminates parallelism)
2. Use start_code_task instead (inherits CLAUDE_CODE_WORKSPACE_HOST_PATHS, different permission model)
3. Batch multiple operations into single large tasks (reduces prompt count but increases complexity)

None of these are good solutions. They all work around the permission model rather than fixing it.

Related Issues

This problem has been reported multiple times and closed without resolution:

• #37713 (Dispatch sessions fully isolated, closed as "invalid")
• #22665 (subagents don't inherit permission allowlist, closed as duplicate of #18950)
• #27661 (subagents should inherit parent hooks and permissions)
• #34604 (default workspace folder, closed as duplicate of #27514)

The pattern across all of these is the same: child sessions need to inherit parent permissions.

Proposed Implementation

When start_task creates a child session, propagate the parent's mounted directory paths to the child session's filesystem scope. No additional user prompt needed because the user already authorised access in the parent session.

If full inheritance is a security concern, an alternative would be a user setting:

{
  "cowork": {
    "inheritMountsToChildSessions": true
  }
}

Environment

• Windows 11 (ARM/Snapdragon)
• Claude Desktop (latest, April 2026)
• Cowork mode with Dispatch
• Workspace: single folder (C:\Users\User\Projects) used across all sessions