improved preloading

frontend/src/config/preload.config.ts

@@ -20,10 +20,10 @@ export const PRELOAD_CONFIG = {
     currentPage: 1000,
     neighborBase: 500,
     assetType: {
+      transition: 150, // Transitions preloaded for faster start
       image: 100, // Backgrounds load first
       audio: 50,
       video: 30,
-      // Note: transitions are cached on first playback, not preloaded
     } as Record<string, number>,
     variant: {
       thumbnail: 50,
@@ -68,11 +68,11 @@ export const PRELOAD_CONFIG = {
   // Partial preload settings (online mode only)
   // Download only first N bytes of videos/audio for faster Phase 1 completion
   // Playback uses presigned URL directly (browser handles remaining buffering)
-  // Note: Transitions are cached on first playback, not preloaded
   partialPreload: {
     enabled: true,
     videoMaxBytes: 5 * 1024 * 1024, // 5MB (~5 seconds of video)
     audioMaxBytes: 512 * 1024, // 512KB (~5 seconds of audio)
+    transitionMaxBytes: 3 * 1024 * 1024, // 3MB (~3 seconds of transition video)
   },
 
   // Asset URL field names in element content_json (camelCase)

frontend/src/hooks/useNeighborGraph.ts

@@ -74,14 +74,12 @@ function extractAssetsFromContent(
       for (const [key, value] of Object.entries(obj)) {
         if (typeof value === 'string' && value && urlFields.includes(key)) {
           // Classify asset type based on field name
-          // Skip transition fields - transitions are cached on first playback
           const lowerKey = key.toLowerCase();
-          if (lowerKey.includes('transition')) {
-            continue; // Skip transitions
-          }
 
-          let assetType: 'video' | 'audio' | 'image';
+          let assetType: 'video' | 'audio' | 'image' | 'transition';
-          if (lowerKey.includes('video')) {
+          if (lowerKey.includes('transition')) {
+            assetType = 'transition';
+          } else if (lowerKey.includes('video')) {
             assetType = 'video';
           } else if (lowerKey.includes('audio')) {
             assetType = 'audio';
@@ -239,14 +237,25 @@ export function useNeighborGraph(
         });
       });
 
-      // Add transition videos (transition is eagerly loaded in page_links)
+      // Extract transition videos from page_links for preloading
       const matchingLinks = pageLinks.filter(
         (link) =>
           link.is_active !== false && pageIds.includes(link.from_pageId || ''),
       );
 
-      // Note: Transition videos are NOT extracted for preloading.
+      matchingLinks.forEach((link) => {
-      // They are cached on first playback via useTransitionPlayback.cacheBlob()
+        // Extract transition video URL from link.transition
+        const transition = link.transition as { video_url?: string } | undefined;
+        if (transition?.video_url && !seenUrls.has(transition.video_url)) {
+          seenUrls.add(transition.video_url);
+          assets.push({
+            url: transition.video_url,
+            pageId: link.from_pageId || '',
+            assetType: 'transition',
+            priority: 0, // Will be calculated later with transition priority
+          });
+        }
+      });
 
       return assets;
     };

frontend/src/hooks/usePreloadOrchestrator.ts

@@ -529,12 +529,18 @@ export function usePreloadOrchestrator(
     ) => {
       // Helper to determine max bytes for partial preload (online mode only)
       // IMPORTANT: Only applies to NEIGHBOR pages, not the current page
+      // Transitions always use partial preload (regardless of page)
       const getMaxBytesForAsset = (
         assetType: 'image' | 'video' | 'audio' | 'transition' | 'other',
         isNeighborPage: boolean,
       ): number | undefined => {
         if (!PRELOAD_CONFIG.partialPreload.enabled) return undefined;
 
+        // Transitions always use partial preload - they need just enough to start quickly
+        if (assetType === 'transition') {
+          return PRELOAD_CONFIG.partialPreload.transitionMaxBytes;
+        }
+
         // Current page assets should be fully downloaded for best UX
         if (!isNeighborPage) return undefined;
 
@@ -557,11 +563,6 @@ export function usePreloadOrchestrator(
         assetType: 'image' | 'video' | 'audio' | 'transition' | 'other',
         pageId: string,
       ): Promise<void> | null => {
-        // Skip transitions - they're cached on first playback via useTransitionPlayback
-        if (assetType === 'transition') {
-          return null;
-        }
-
         const resolvedUrl = resolveUrl(storageKey, presignedUrls);
         if (!resolvedUrl) return null;
 
@@ -577,8 +578,9 @@ export function usePreloadOrchestrator(
         // Determine if partial preload applies (neighbor pages only, media files only)
         const isNeighborPage = pageId !== currentPageId;
         const maxBytes = getMaxBytesForAsset(assetType, isNeighborPage);
-        // For partial downloads, don't create blob URL - playback uses presigned URL
+        // Create blob URL for images (instant navigation) and full downloads
-        const createBlobUrl = maxBytes === undefined;
+        // Partial downloads (video/audio/transition) use presigned URL directly for playback
+        const createBlobUrl = assetType === 'image' || maxBytes === undefined;
 
         return downloadManager
           .addJob({
@@ -690,11 +692,11 @@ export function usePreloadOrchestrator(
       // ============================================
       // PHASE 2: Preload everything else (don't wait)
       // - Current page element assets (full downloads)
-      // - Transition videos (partial preload - 3MB)
       // - Neighbor page backgrounds (partial preload for video/audio)
       // - Neighbor page element assets (partial preload for video/audio)
+      // - Transition videos from page links (partial preload - 3MB)
       // ============================================
-      logger.info('[PRELOAD] Phase 2: Preloading transitions and neighbors');
+      logger.info('[PRELOAD] Phase 2: Preloading neighbors and transitions');
 
       // Current page element assets (moved from Phase 1 for faster startup)
       const currentPageAssets = assets.filter(