fix(compare): census-sourced FSM/EAL benchmarks; never fall back across measure definitions

The FSM chip anchored against disadvantaged_pct (a different measure,
FSM6+CLA) whenever fsm_pct was null — which it always was, since the
performance df has no fsm_pct. New fact_census_benchmarks mart supplies
pupil-weighted FSM/EAL means per phase; the KS2-column medians that
produced a bogus 50% 'secondary disadvantaged' anchor are gone.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB

nextjs-app/components/compare/CompareCommunity.tsx

@@ -33,7 +33,10 @@ export function CompareCommunity({
   const bench = isSecondary ? benchmarks?.secondary : benchmarks?.primary;
 
   const fsmChip = (value: number | null) => {
-    const anchor = bench?.fsm_pct ?? bench?.disadvantaged_pct ?? null;
+    // FSM is anchored only against a real FSM benchmark (census-sourced,
+    // pupil-weighted). disadvantaged_pct is a different measure (FSM6+CLA)
+    // — never fall back across definitions; no anchor means no chip.
+    const anchor = bench?.fsm_pct ?? null;
     if (value == null || anchor == null) return null;
     const v = verdict(value, anchor, 3);
     return (