planning-estimatelisted

<!-- planning:contract --> ## Owns How long, expressed as a range with the reasons it is that wide. **The drivers of the range are the deliverable; the number is a summary of them.** Phases: `REFERENCE → SIZE → AGGREGATE → BUFFER → STRESS`. ## Before starting - **Require shaped tasks.** A task with no observable done condition cannot be sized — you would be estimating a description - **Find comparable actuals first.** An estimate anchored on something that actually happened beats one anchored on how the work feels; where no comparable exists, say so and widen the range - **Establish the real capacity, not the headcount.** State the assumed productive fraction and what it is based on <!-- 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/SIZING.md` says whi