feat(iace): 50% display threshold — weak matches shown as separate

Matches below 50% are now split:
- GT entries → "Fehlend" tab (not matched by engine)
- Engine entries → "Engine Findings" tab (additional findings)
Only matches >= 50% shown in "Zugeordnet" tab.

Coverage score now counts only real matches (>= 50%).
"Extra" tab renamed to "Engine Findings" for clarity.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin-compliance/app/sdk/iace/[projectId]/benchmark/page.tsx

@@ -12,7 +12,9 @@ export default function BenchmarkPage() {
   const { result, gtLoaded, gtEntryCount, loading, error, importGT, runBenchmark } = useBenchmark(projectId)
   const [gtProjectId, setGtProjectId] = useState('')
 
-  const coveragePct = result ? Math.round(result.coverage_score * 100) : 0
+  // Only count matches >= 50% as real coverage
+  const realMatchCount = result ? (result.matched_pairs?.filter(m => m.match_score >= 0.5).length || 0) : 0
+  const coveragePct = result ? Math.round(realMatchCount * 100 / Math.max(result.total_gt, 1)) : 0
   const measurePct = result ? Math.round(result.measure_coverage * 100) : 0
 
   return (
@@ -74,7 +76,7 @@ export default function BenchmarkPage() {
             <ScoreCard
               label="Hazard Coverage"
               value={`${coveragePct}%`}
-              sub={`${result.matched_pairs?.length || 0} / ${result.total_gt} erkannt`}
+              sub={`${realMatchCount} / ${result.total_gt} erkannt (>= 50% Match)`}
               color={coveragePct >= 80 ? 'green' : coveragePct >= 50 ? 'yellow' : 'red'}
             />
             <ScoreCard