Show detected page number in session header

Extracts page_number from grid_editor_result when opening a session
and displays it as "S. 233" badge in the SessionHeader, next to the
category and GT badges.

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

admin-lehrer/app/(admin)/ai/ocr-kombi/page.tsx

@@ -27,6 +27,7 @@ function OcrKombiContent() {
     loadingSessions,
     activeCategory,
     isGroundTruth,
+    pageNumber,
     steps,
     gridSaveRef,
     groupedSessions,
@@ -142,6 +143,7 @@ function OcrKombiContent() {
           sessionName={sessionName}
           activeCategory={activeCategory}
           isGroundTruth={isGroundTruth}
+          pageNumber={pageNumber}
           onUpdateCategory={(cat) => updateCategory(sessionId, cat)}
         />
       )}