subagents-blocked-from-writing-skills-dir

All parallel subagents dispatched with Write access to /root/.claude/skills/ were blocked by sandbox restrictions — even when the main agent can write there freely. This caused all 4 parallel Stage 2 agents to fail silently. For any work touching /root/.claude/skills/, the main agent must perform all writes directly; subagents can only read or operate on non-sandboxed paths.