feat:음성입력 STT 사용량 AI 토큰 추적 연동

logSttUsage 엔드포인트 추가, 녹음 종료 시 duration 전송
AI 토큰 사용량에 '공사현장사진대지-음성입력' 카테고리로 기록

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

routes/web.php

@@ -1325,5 +1325,6 @@
         Route::delete('/{id}', [ConstructionSitePhotoController::class, 'destroy'])->name('destroy');
         Route::delete('/{id}/photo/{type}', [ConstructionSitePhotoController::class, 'deletePhoto'])->name('delete-photo');
         Route::get('/{id}/download/{type}', [ConstructionSitePhotoController::class, 'downloadPhoto'])->name('download');
+        Route::post('/log-stt-usage', [ConstructionSitePhotoController::class, 'logSttUsage'])->name('log-stt-usage');
     });
 });