planner-orchestration

# Single-Session Orchestration The user-started primary conversation owns durable artifacts, integration judgment, and user communication. Platform-provided explorers and other predefined subagents may continue to serve the harness's normal investigation workflow. This skill governs planned implementation delegation, not the platform's general exploration behavior. ## Model Checkpoints The user, not the harness, selects the model. Keep each phase in the primary conversation so the active model, transcript, and costs are visible in one place. 1. **Design checkpoint — strong model.** Use the user's strong model for clarification, codebase investigation, requirements, system designs, plans, work-order decomposition, and high-risk decisions. Default Codex guidance is GPT-5.6 Sol/high. 2. **Design-package handoff.** Once the requirements, system design, plan, and work orders are ready, summarize their paths and end the turn. Do not call `ask_user_question_kandev` (or an equivalent approval prompt) to ask the user to approve the package or switch models. The user reviews the files, switches the main session if desired, and sends a later explicit implementation request. The files may remain `draft`/`pending`; do not wait for a separate approval marker. 3. **Execution checkpoint.** After that explicit request, read the work order, mark it `in_progress`, implement with `/tdd`, run its exact targeted checks, and mark it `done`. Work sequentially thr...