fix: prevent recurring Codex MCP and Brain warnings

[pacphi]

Summary

• qualify RuvNet Brain continuity from the exact hook contract rather than a point-version allowlist
• recognize and safely repair the legacy Codex Ruflo transport when its only child setting is the kit-managed browser environment
• add regression coverage for the 4.3.18 and future continuity contracts, managed-child repair, and user-owned-child preservation

Verification

• pnpm test
• pnpm run typecheck
• pnpm run lint (existing warnings only)
• pnpm run build

Live machine verification removed the legacy claude-flow entry, preserving the workspace-aware ruflo and Agentic QE registrations.