Slot click now opens an inline editor panel:
- Pick from saved recipes via dropdown (pre-loaded on mount)
- Or type a custom label
- Clear slot button when a slot is already filled
- Save/Cancel with loading state
Add meal type opens a chip picker showing the types not yet active
(breakfast / lunch / snack minus whatever is already on the plan).
Selecting one calls the new PATCH /meal-plans/{plan_id} endpoint.
Backend:
- PATCH /meal-plans/{plan_id} with UpdatePlanRequest(meal_types)
- store.update_meal_plan_types() UPDATE ... RETURNING *
- 409 on IntegrityError in create_plan (already in place)