Revive the China-specific non-market economy unit

Research notes

Cluster negative search E&C-1 (chapter log): Federal Register full text since 2025-01-20 for "self-initiation" (1 hit, a 2025-03-31 correction notice), "surrogate country" (73 hits, all individual AD/CVD case notices), "non-market economy" methodology (131, same), "Top Markets" (0); plus a jq pass over every in-window Federal Register record whose agency is the International Trade Administration, with the individual AD/CVD case notices filtered out. Also Federal Register full text since 2025-01-20 for "non-market economy" unit, "China Enforcement" and "Office of Policy" Commerce; and a grep of the FY2026 and FY2027 budget documents for a China unit at ITA (the FY2027 Budget cuts ITA Global Markets by $150 million and adds $10 million for trade enforcement generally, naming no unit).