feat:튜토리얼 영상 멀티스텝 개선 (8초 → 30초~2분)

- ScreenAnalysisService: Gemini 프롬프트를 멀티스텝(3~5 steps) 출력으로 변경 + 하위 호환 fallback
- SlideAnnotationService: 스포트라이트 효과(annotateSlideWithSpotlight), 인트로/아웃트로 슬라이드 생성
- TutorialVideoJob: screen→steps 중첩 루프 + 인트로/아웃트로 씬 추가
- index.blade.php: 단계별 나레이션 편집 UI + 예상 시간 표시

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

app/Jobs/TutorialVideoJob.php

@@ -78,6 +78,12 @@ public function handle(
 
                 $tutorial->update(['analysis_data' => $analysisData]);
                 $totalCost += 0.01; // Gemini Vision
+            } else {
+                // DB 캐시된 기존 형식도 steps[] 형식으로 변환
+                $analysisData = array_map(
+                    fn ($screen) => $screenAnalysis->ensureStepsFormatPublic($screen),
+                    $analysisData
+                );
             }
 
             $tutorial->updateProgress(TutorialVideo::STATUS_ANALYZING, 10, 'AI 분석 완료');
@@ -90,41 +96,84 @@ public function handle(
             $scenes = [];
             $screenshots = $tutorial->screenshots ?? [];
 
+            // 전체 step 수 계산 (진행 배지용)
+            $totalSteps = 0;
+            foreach ($analysisData as $screen) {
+                $totalSteps += count($screen['steps'] ?? []);
+            }
+
+            // 인트로 슬라이드 생성
+            $introPath = "{$workDir}/slide_intro.png";
+            $introTitle = $tutorial->title ?? 'SAM 사용자 매뉴얼';
+            $introResult = $slideAnnotation->createIntroSlide($introTitle, $introPath);
+            if ($introResult) {
+                $slidePaths[] = $introResult;
+                $durations[] = 3;
+                $scenes[] = [
+                    'scene_number' => 1,
+                    'narration' => "{$introTitle}. SAM 사용법을 안내합니다.",
+                    'duration' => 3,
+                ];
+            }
+
+            // 중첩 루프: screen → steps
+            $globalStepNum = 0;
             foreach ($analysisData as $i => $screen) {
                 $screenNum = $screen['screen_number'] ?? ($i + 1);
                 $imagePath = $screenshots[$i] ?? null;
+                $steps = $screen['steps'] ?? [];
 
                 if (! $imagePath || ! file_exists($imagePath)) {
                     Log::warning("TutorialVideoJob: 스크린샷 없음 - index {$i}");
                     continue;
                 }
 
-                $outputSlide = "{$workDir}/slide_{$screenNum}.png";
+                foreach ($steps as $step) {
+                    $globalStepNum++;
+                    $stepNum = $step['step_number'] ?? $globalStepNum;
+                    $sceneNumber = $screenNum * 100 + $stepNum;
 
-                $result = $slideAnnotation->annotateSlide(
-                    $imagePath,
-                    $screen['ui_elements'] ?? [],
-                    $screenNum,
-                    $screen['narration'] ?? "화면 {$screenNum}",
-                    $outputSlide
-                );
+                    $outputSlide = "{$workDir}/slide_{$sceneNumber}.png";
 
-                if ($result) {
-                    $slidePaths[] = $result;
-                    $duration = $screen['duration'] ?? 8;
-                    $durations[] = $duration;
-                    $scenes[] = [
-                        'scene_number' => $screenNum,
-                        'narration' => $screen['narration'] ?? '',
-                        'duration' => $duration,
-                    ];
+                    $result = $slideAnnotation->annotateSlideWithSpotlight(
+                        $imagePath,
+                        $step['focused_element'] ?? null,
+                        $globalStepNum,
+                        $totalSteps,
+                        $step['narration'] ?? "단계 {$stepNum}",
+                        $outputSlide
+                    );
+
+                    if ($result) {
+                        $slidePaths[] = $result;
+                        $duration = $step['duration'] ?? 6;
+                        $durations[] = $duration;
+                        $scenes[] = [
+                            'scene_number' => $sceneNumber,
+                            'narration' => $step['narration'] ?? '',
+                            'duration' => $duration,
+                        ];
+                    }
                 }
 
-                $progress = 15 + (int) (($i + 1) / count($analysisData) * 15);
-                $tutorial->updateProgress(TutorialVideo::STATUS_GENERATING_SLIDES, $progress, "슬라이드 {$screenNum} 생성 완료");
+                $progress = 15 + (int) (($i + 1) / count($analysisData) * 13);
+                $tutorial->updateProgress(TutorialVideo::STATUS_GENERATING_SLIDES, $progress, "화면 {$screenNum} 슬라이드 생성 완료");
             }
 
-            if (empty($slidePaths)) {
+            // 아웃트로 슬라이드 생성
+            $outroPath = "{$workDir}/slide_outro.png";
+            $outroResult = $slideAnnotation->createOutroSlide($introTitle, $outroPath);
+            if ($outroResult) {
+                $slidePaths[] = $outroResult;
+                $durations[] = 3;
+                $scenes[] = [
+                    'scene_number' => 999,
+                    'narration' => '이상으로 안내를 마칩니다. 감사합니다.',
+                    'duration' => 3,
+                ];
+            }
+
+            if (count($slidePaths) <= 2) { // 인트로+아웃트로만 있으면 실패
                 $tutorial->markFailed('슬라이드 생성에 실패했습니다');
                 return;
             }