Concept-level taxonomy.

Curated macro indicators decoupled from any one source. Each concept (e.g. CPI YoY) maps to one or more concrete series — geography × source × frequency × seasonal-adjustment — so values from FRED, ECB, OECD, BIS, and Eurostat coexist behind a single canonical key. Observations are vintage-aware: every revision is a new row, never an update.