feat: [file] API Resource에서 image_url (presigned URL) 반환

- File 모델에 presignedUrl() 메서드 추가
- GuiderailModelResource: image_url + components[].image_url 반환
- BendingItemResource: image_url 반환
- 소비자(MNG, React)가 별도 처리 없이 R2 직접 로드 가능

app/Http/Resources/Api/V1/BendingItemResource.php

@@ -40,6 +40,7 @@ public function toArray(Request $request): array
             'registration_date' => $this->getOption('registration_date'),
             // 이미지
             'image_file_id' => $this->getImageFileId(),
+            'image_url' => $this->getImageUrl(),
             // 추적
             'legacy_bending_id' => $this->legacy_bending_id,
             'legacy_bending_num' => $this->legacy_bending_id, // MNG2 호환
@@ -60,13 +61,21 @@ public function toArray(Request $request): array
         ];
     }
 
-    private function getImageFileId(): ?int
+    private function getImageFile(): ?\App\Models\Commons\File
     {
-        $file = $this->files()
+        return $this->files()
             ->where('field_key', 'bending_diagram')
             ->orderByDesc('id')
             ->first();
+    }
 
-        return $file?->id;
+    private function getImageFileId(): ?int
+    {
+        return $this->getImageFile()?->id;
+    }
+
+    private function getImageUrl(): ?string
+    {
+        return $this->getImageFile()?->presignedUrl();
     }
 }

app/Http/Resources/Api/V1/GuiderailModelResource.php

@@ -48,8 +48,9 @@ public function toArray(Request $request): array
             'modified_by' => $this->getOption('modified_by'),
             // 이미지
             'image_file_id' => $this->getImageFileId(),
+            'image_url' => $this->getImageUrl(),
             // 부품 조합
-            'components' => $components,
+            'components' => $this->enrichComponentsWithImageUrls($components),
             'material_summary' => $materialSummary,
             'component_count' => count($components),
             // 메타
@@ -58,7 +59,7 @@ public function toArray(Request $request): array
         ];
     }
 
-    private function getImageFileId(): ?int
+    private function getImageFile(): ?\App\Models\Commons\File
     {
         $file = \App\Models\Commons\File::where('document_id', $this->id)
             ->where('document_type', 'bending_model')
@@ -74,7 +75,40 @@ private function getImageFileId(): ?int
                 ->first();
         }
 
-        return $file?->id;
+        return $file;
+    }
+
+    private function getImageFileId(): ?int
+    {
+        return $this->getImageFile()?->id;
+    }
+
+    private function getImageUrl(): ?string
+    {
+        return $this->getImageFile()?->presignedUrl();
+    }
+
+    private function enrichComponentsWithImageUrls(array $components): array
+    {
+        $fileIds = array_filter(array_column($components, 'image_file_id'));
+        if (empty($fileIds)) {
+            return $components;
+        }
+
+        $files = \App\Models\Commons\File::whereIn('id', $fileIds)
+            ->whereNull('deleted_at')
+            ->get()
+            ->keyBy('id');
+
+        foreach ($components as &$comp) {
+            $fileId = $comp['image_file_id'] ?? null;
+            $comp['image_url'] = $fileId && isset($files[$fileId])
+                ? $files[$fileId]->presignedUrl()
+                : null;
+        }
+        unset($comp);
+
+        return $components;
     }
 
     private function calcMaterialSummary(array $components): array

app/Models/Commons/File.php

@@ -98,6 +98,21 @@ public function fileable()
         return $this->morphTo();
     }
 
+    /**
+     * R2 Presigned URL 생성 (30분 유효)
+     */
+    public function presignedUrl(int $minutes = 30): ?string
+    {
+        if (! $this->file_path) {
+            return null;
+        }
+
+        return Storage::disk('r2')->temporaryUrl(
+            $this->file_path,
+            now()->addMinutes($minutes)
+        );
+    }
+
     /**
      * Get the full storage path
      */