subagent-stall-root-causes-and-fixes

Subagents stall on 4 distinct mechanics: (1) settings.local.json missing Edit/Write wildcards causes permission prompts mid-execution, (2) isolation:worktree mode returns changes as a diff not applied to live tree — never use for production, (3) session-scoped MCPs registered after subagent dispatch are invisible to those subagents, (4) specialized agent types (Explore, claude-code-guide) have curtailed toolsets — always dispatch general-purpose for execution work. Pre-approving broad safe patterns in permissions.allow before dispatching eliminates all stalls.