NEW: Meta key migration — new WooCommerce order attribution writes use _shulmanattrib_utm_* and _shulmanattrib_fc_* keys (replacing _ute_utm_* / _ute_fc_* for new data)
NEW: Centralised read/write helpers — get_order_utm_meta(), update_order_utm_meta(), get_order_fc_meta(), update_order_fc_meta(), get_order_status_meta() — all reads prefer new keys and fall back to legacy transparently
NEW: Existing orders stored under legacy _ute_* keys continue to work everywhere: orders column, meta box, export, filters — no data migration needed
NEW: UTM source filter in Orders page queries both new and legacy meta keys so old and new orders appear together
NEW: Key Insights panel in dashboard — rule-based deterministic insights (top source, unattributed rate, top combination, diversification signal)