Clarify - Tier Reference

Reference, not canonical. The per-step tier files that used to sit in each Clarify step folder. The chapter README's tier table is the summary the process now runs from; these hold the longer reasoning behind each cell (bounds, upgrade-trigger rationale, handoffs) while the table is reviewed.

baseline.md defines the Clarify Baseline itself - the non-removable minimum included in every S build - which the Baseline column below breaks down per step.

Step	Baseline	Focused	Core	Full
1.1 Stakeholders	baseline	focused	core	full
1.2 Users	baseline	focused	core	full
1.3 Current state	baseline	focused	core	full
1.4 Market & search	baseline	focused	core	full
1.5 Synthesis	baseline	focused	core	full