fix: cleanup-workflow filter, workflow load validation, media hydration guard

- cleanup-workflow.js: Filter only embedded data: images from outputGallery
  instead of wiping entire array; preserve imageRef/video on output nodes
- workflow/route.ts: Validate parsed.version is number, nodes/edges are
  arrays; sort candidates by mtime desc for deterministic file selection
- mediaStorage.ts: Guard against undefined mediaData in loadMediaById
  before caching/returning

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

scripts/cleanup-workflow.js

@@ -26,12 +26,15 @@ workflow.nodes.forEach((node, index) => {
     const imageCount = node.data.images.filter(img => img && img.startsWith('data:')).length;
 
     if (imageCount > 0) {
+      const removedImages = node.data.images.filter(img => img && img.startsWith('data:'));
+      const removedSize = removedImages.reduce((sum, img) => sum + img.length, 0);
+
       console.log(`\nNode ${index} (${node.id}):`);
       console.log(`  Found ${imageCount} embedded images`);
-      console.log(`  Size: ${(sizeBefore / 1024 / 1024).toFixed(2)} MB`);
+      console.log(`  Size: ${(removedSize / 1024 / 1024).toFixed(2)} MB`);
 
-      node.data.images = [];
-      totalSizeBefore += sizeBefore;
+      node.data.images = node.data.images.filter(img => !(img && img.startsWith('data:')));
+      totalSizeBefore += removedSize;
       cleaned = true;
     }
   }
@@ -43,10 +46,6 @@ workflow.nodes.forEach((node, index) => {
     console.log(`  Size: ${(sizeBefore / 1024 / 1024).toFixed(2)} MB`);
 
     node.data.image = null;
-    node.data.imageRef = undefined;
-    if (node.data.video) {
-      node.data.video = null;
-    }
     totalSizeBefore += sizeBefore;
     cleaned = true;
   }

src/app/api/workflow/route.ts

@@ -189,13 +189,29 @@ export async function GET(request: NextRequest) {
       const entries = await fs.readdir(directoryPath);
       const jsonFiles = entries.filter(f => f.endsWith(".json"));
 
+      // Gather candidates with mtime for deterministic selection (newest first)
+      const candidates: { jsonFile: string; filePath: string; mtime: number }[] = [];
       for (const jsonFile of jsonFiles) {
         try {
           const filePath = path.join(directoryPath, jsonFile);
+          const stat = await fs.stat(filePath);
+          candidates.push({ jsonFile, filePath, mtime: stat.mtimeMs });
+        } catch {
+          continue;
+        }
+      }
+      candidates.sort((a, b) => b.mtime - a.mtime);
+
+      for (const { jsonFile, filePath } of candidates) {
+        try {
           const content = await fs.readFile(filePath, "utf-8");
           const parsed = JSON.parse(content);
 
-          if (parsed.version && parsed.nodes && parsed.edges) {
+          if (
+            typeof parsed.version === "number" &&
+            Array.isArray(parsed.nodes) &&
+            Array.isArray(parsed.edges)
+          ) {
             const filename = path.basename(jsonFile, ".json");
             logger.info('file.load', 'Workflow loaded from directory', {
               directoryPath,

src/utils/mediaStorage.ts

@@ -1100,11 +1100,15 @@ async function loadMediaById(
       genResult = await response.json();
     }
 
-    const mediaData = mediaType === "video" ? genResult.video : genResult.audio;
     if (!genResult.success) {
       console.log(`${mediaType} not found: ${mediaId}`);
       return "";
     }
+    const mediaData = mediaType === "video" ? genResult.video : genResult.audio;
+    if (!mediaData) {
+      console.log(`${mediaType} not found or invalid payload: ${mediaId}`);
+      return "";
+    }
     loadedMedia.set(mediaId, mediaData);
     return mediaData;
   }