planning-decomposelisted

<!-- planning:contract --> ## Owns The shape of the work once the approach is settled — what the tasks are, what each depends on, what order retires the most uncertainty, and where the system stays deployable. **It never estimates durations.** Phases: `SLICE → VERIFY → LINK ��� SEQUENCE → MARK`. ## Before starting - **Confirm the approach is chosen.** Slicing before choosing plans work that may not happen, and the sunk effort argues for the approach afterwards - **Take the goals from the brief.** A task serving no `G-n` is cut, or justified in writing as enabling work - **Stop splitting when a subtask could not be handed to a different person without a conversation.** That is the floor, not a size in hours <!-- deliver:sizing --> - **Declare the tier before anything else**, read off the work and stated at the top of the deliverable. `S` — under a day, reversible: one brief in the response, **no files, no handoff**. `M` — multi-day, single owner: the brief and the plan. `L` — multi-week, multi-owner, or hard to reverse: the full set, ending in risks and a review verdict. **Over-planning an `S` is a failure of the same weight as under-planning an `L`** - **The planning gate stops the run at the phase that owns the condition** — the goal cannot be stated in one sentence without "and", no success criterion is measurable, a load-bearing assumption is cheap to verify and unverified, or the person has already decided and is asking for execution; `_planning