fix: bei Cluster-Ueberschuss die breitesten N Cluster waehlen

Wenn mehr Pixel-Cluster als Text-Gruppen existieren (z.B. wegen
Box-Rahmenlinien), werden jetzt die N breitesten Cluster ausgewaehlt
statt naiv clusters[i]→groups[i] zuzuordnen. Text-Cluster sind
breiter als Rahmenlinien-Cluster.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-lehrer/components/ocr-overlay/usePixelWordPositions.ts

@@ -126,10 +126,20 @@ export function usePixelWordPositions(
 
         const wordPos: WordPosition[] = []
 
-        if (groups.length > 1 && clusters.length >= groups.length) {
-          // Multiple text groups with enough clusters: map each group to a cluster
+        // When more clusters than groups, pick the N widest clusters
+        // (text clusters are wider than box-border clusters)
+        let matchClusters = clusters
+        if (groups.length > 1 && clusters.length > groups.length) {
+          matchClusters = [...clusters]
+            .sort((a, b) => (b.end - b.start) - (a.end - a.start))
+            .slice(0, groups.length)
+            .sort((a, b) => a.start - b.start)
+        }
+
+        if (groups.length > 1 && matchClusters.length >= groups.length) {
+          // Multiple text groups with matching clusters
           for (let i = 0; i < groups.length; i++) {
-            const cl = clusters[i]
+            const cl = matchClusters[i]
             const clusterW = cl.end - cl.start + 1
             const measured = ctx.measureText(groups[i])
             const autoFontPx = refFontSize * (clusterW / measured.width)