Heavy context-gather skill for ambiguous SDD requests. Forces premise challenge plus 3 implementation alternatives before writing anything. Output is a transient design-doc note intended as Stage 1.5 Context Intake input for `/immutable:prd`. Use when the user is exploring a new feature, the problem is fuzzy, or you sense they are about to pick option 1 without considering options 2 or 3. Triggers - "/immutable:office-hours", "오피스 아워", "premise challenge", "explore options".
