Add version control to track editor, restyle story list

- Story items can be pinned to a specific generation version via
  toolbar dropdown (shows when clip is selected and has >1 version)
- version_id column on story_items with migration, validated against
  the generation's versions before saving
- Split/duplicate preserve the source clip's pinned version
- Export and playback resolve version-specific audio paths
- Extracted _build_item_detail helper in stories.py (DRY cleanup)
- Story list restyled from rounded cards to flat rows with rounded
  hover/active states, gradient header fade, and dynamic bottom
  padding that accounts for track editor + generate box

app/src/components/StoriesTab/StoryList.tsx

@@ -1,4 +1,4 @@
-import { Plus, BookOpen, MoreHorizontal, Pencil, Trash2 } from 'lucide-react';
+import { BookOpen, MoreHorizontal, Pencil, Plus, Trash2 } from 'lucide-react';
 import { useState } from 'react';
 import {
   AlertDialog,
@@ -29,7 +29,13 @@ import { Input } from '@/components/ui/input';
 import { Label } from '@/components/ui/label';
 import { Textarea } from '@/components/ui/textarea';
 import { useToast } from '@/components/ui/use-toast';
-import { useStories, useCreateStory, useUpdateStory, useDeleteStory } from '@/lib/hooks/useStories';
+import {
+  useCreateStory,
+  useDeleteStory,
+  useStories,
+  useStory,
+  useUpdateStory,
+} from '@/lib/hooks/useStories';
 import { cn } from '@/lib/utils/cn';
 import { formatDate } from '@/lib/utils/format';
 import { useStoryStore } from '@/stores/storyStore';
@@ -38,6 +44,8 @@ export function StoryList() {
   const { data: stories, isLoading } = useStories();
   const selectedStoryId = useStoryStore((state) => state.selectedStoryId);
   const setSelectedStoryId = useStoryStore((state) => state.setSelectedStoryId);
+  const trackEditorHeight = useStoryStore((state) => state.trackEditorHeight);
+  const { data: selectedStory } = useStory(selectedStoryId);
   const createStory = useCreateStory();
   const updateStory = useUpdateStory();
   const deleteStory = useDeleteStory();
@@ -170,20 +178,29 @@ export function StoryList() {
   }
 
   const storyList = stories || [];
+  const hasTrackEditor = selectedStoryId && selectedStory && selectedStory.items.length > 0;
 
   return (
-    <div className="flex flex-col h-full min-h-0">
-      {/* Header */}
-      <div className="flex items-center justify-between mb-4 px-1">
-        <h2 className="text-2xl font-bold">Stories</h2>
-        <Button onClick={() => setCreateDialogOpen(true)} size="sm">
-          <Plus className="mr-2 h-4 w-4" />
-          New Story
-        </Button>
+    <div className="h-full flex flex-col relative overflow-hidden">
+      {/* Scroll Mask */}
+      <div className="absolute top-0 left-0 right-0 h-16 bg-gradient-to-b from-background to-transparent z-10 pointer-events-none" />
+
+      {/* Fixed Header */}
+      <div className="absolute top-0 left-0 right-0 z-20">
+        <div className="flex items-center justify-between mb-4 px-1">
+          <h2 className="text-2xl font-bold">Stories</h2>
+          <Button onClick={() => setCreateDialogOpen(true)} size="sm">
+            <Plus className="mr-2 h-4 w-4" />
+            New Story
+          </Button>
+        </div>
       </div>
 
-      {/* Story List */}
-      <div className="flex-1 min-h-0 overflow-y-auto space-y-2">
+      {/* Scrollable Story List */}
+      <div
+        className="flex-1 overflow-y-auto pt-14 relative z-0"
+        style={{ paddingBottom: hasTrackEditor ? `${trackEditorHeight + 140}px` : '170px' }}
+      >
         {storyList.length === 0 ? (
           <div className="text-center py-12 px-5 border-2 border-dashed border-muted rounded-2xl text-muted-foreground">
             <BookOpen className="h-12 w-12 mx-auto mb-4 opacity-50" />
@@ -191,75 +208,68 @@ export function StoryList() {
             <p className="text-xs mt-2">Create your first story to get started</p>
           </div>
         ) : (
-          storyList.map((story) => (
-            <div
-              key={story.id}
-              role="button"
-              tabIndex={0}
-              className={cn(
-                'h-24 p-4 border rounded-2xl transition-colors group flex items-center cursor-pointer',
-                selectedStoryId === story.id && 'bg-muted border-primary',
-              )}
-              aria-label={
-                selectedStoryId === story.id
-                  ? `Story ${story.name}, ${story.item_count} ${story.item_count === 1 ? 'item' : 'items'}, ${formatDate(story.updated_at)}. Selected. Press Enter to select.`
-                  : `Story ${story.name}, ${story.item_count} ${story.item_count === 1 ? 'item' : 'items'}, ${formatDate(story.updated_at)}. Press Enter to select.`
-              }
-              aria-pressed={selectedStoryId === story.id}
-              onClick={() => setSelectedStoryId(story.id)}
-              onKeyDown={(e) => {
-                if (e.target !== e.currentTarget) return;
-                if (e.key === 'Enter' || e.key === ' ') {
-                  e.preventDefault();
-                  setSelectedStoryId(story.id);
-                }
-              }}
-            >
-              <div className="flex items-start justify-between gap-2 w-full min-w-0">
-                <div className="flex-1 min-w-0 text-left overflow-hidden">
-                  <h3 className="font-medium truncate">{story.name}</h3>
-                  {story.description && (
-                    <p className="text-sm text-muted-foreground mt-1 truncate">
-                      {story.description}
-                    </p>
-                  )}
-                  <div className="flex items-center gap-3 mt-2 text-xs text-muted-foreground">
-                    <span>
-                      {story.item_count} {story.item_count === 1 ? 'item' : 'items'}
-                    </span>
-                    <span>•</span>
-                    <span>{formatDate(story.updated_at)}</span>
+          <div className="space-y-0.5">
+            {storyList.map((story) => (
+              <div
+                key={story.id}
+                role="button"
+                tabIndex={0}
+                className={cn(
+                  'px-5 py-3 rounded-lg transition-colors group flex items-center cursor-pointer',
+                  selectedStoryId === story.id ? 'bg-muted' : 'hover:bg-muted/50',
+                )}
+                aria-label={`Story ${story.name}, ${story.item_count} ${story.item_count === 1 ? 'item' : 'items'}, ${formatDate(story.updated_at)}`}
+                aria-pressed={selectedStoryId === story.id}
+                onClick={() => setSelectedStoryId(story.id)}
+                onKeyDown={(e) => {
+                  if (e.target !== e.currentTarget) return;
+                  if (e.key === 'Enter' || e.key === ' ') {
+                    e.preventDefault();
+                    setSelectedStoryId(story.id);
+                  }
+                }}
+              >
+                <div className="flex items-start justify-between gap-2 w-full min-w-0">
+                  <div className="flex-1 min-w-0 text-left overflow-hidden">
+                    <h3 className="text-sm font-medium truncate">{story.name}</h3>
+                    <div className="flex items-center gap-2 mt-1 text-xs text-muted-foreground">
+                      <span>
+                        {story.item_count} {story.item_count === 1 ? 'item' : 'items'}
+                      </span>
+                      <span>·</span>
+                      <span>{formatDate(story.updated_at)}</span>
+                    </div>
                   </div>
+                  <DropdownMenu>
+                    <DropdownMenuTrigger asChild>
+                      <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-7 w-7 opacity-0 group-hover:opacity-100 transition-opacity"
+                        onClick={(e) => e.stopPropagation()}
+                        aria-label={`Actions for ${story.name}`}
+                      >
+                        <MoreHorizontal className="h-3.5 w-3.5" />
+                      </Button>
+                    </DropdownMenuTrigger>
+                    <DropdownMenuContent align="end">
+                      <DropdownMenuItem onClick={() => handleEditClick(story)}>
+                        <Pencil className="mr-2 h-4 w-4" />
+                        Edit
+                      </DropdownMenuItem>
+                      <DropdownMenuItem
+                        onClick={() => handleDeleteClick(story.id)}
+                        className="text-destructive focus:text-destructive"
+                      >
+                        <Trash2 className="mr-2 h-4 w-4" />
+                        Delete
+                      </DropdownMenuItem>
+                    </DropdownMenuContent>
+                  </DropdownMenu>
                 </div>
-                <DropdownMenu>
-                  <DropdownMenuTrigger asChild>
-                    <Button
-                      variant="ghost"
-                      size="icon"
-                      className="h-8 w-8 opacity-0 group-hover:opacity-100 transition-opacity"
-                      onClick={(e) => e.stopPropagation()}
-                      aria-label={`Actions for ${story.name}`}
-                    >
-                      <MoreHorizontal className="h-4 w-4" />
-                    </Button>
-                  </DropdownMenuTrigger>
-                  <DropdownMenuContent align="end">
-                    <DropdownMenuItem onClick={() => handleEditClick(story)}>
-                      <Pencil className="mr-2 h-4 w-4" />
-                      Edit
-                    </DropdownMenuItem>
-                    <DropdownMenuItem
-                      onClick={() => handleDeleteClick(story.id)}
-                      className="text-destructive focus:text-destructive"
-                    >
-                      <Trash2 className="mr-2 h-4 w-4" />
-                      Delete
-                    </DropdownMenuItem>
-                  </DropdownMenuContent>
-                </DropdownMenu>
               </div>
-            </div>
-          ))
+            ))}
+          </div>
         )}
       </div>
 

app/src/components/StoriesTab/StoryTrackEditor.tsx

@@ -1,5 +1,7 @@
 import {
+  Check,
   Copy,
+  GalleryVerticalEnd,
   GripHorizontal,
   Minus,
   Pause,
@@ -12,6 +14,12 @@ import {
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import WaveSurfer from 'wavesurfer.js';
 import { Button } from '@/components/ui/button';
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from '@/components/ui/dropdown-menu';
 import { useToast } from '@/components/ui/use-toast';
 import { apiClient } from '@/lib/api/client';
 import type { StoryItemDetail } from '@/lib/api/types';
@@ -19,6 +27,7 @@ import {
   useDuplicateStoryItem,
   useMoveStoryItem,
   useRemoveStoryItem,
+  useSetStoryItemVersion,
   useSplitStoryItem,
   useTrimStoryItem,
 } from '@/lib/hooks/useStories';
@@ -28,12 +37,14 @@ import { useStoryStore } from '@/stores/storyStore';
 // Clip waveform component with trim support
 function ClipWaveform({
   generationId,
+  versionId,
   width,
   trimStartMs,
   trimEndMs,
   duration,
 }: {
   generationId: string;
+  versionId?: string;
   width: number;
   trimStartMs: number;
   trimEndMs: number;
@@ -79,7 +90,9 @@ function ClipWaveform({
 
     wavesurferRef.current = wavesurfer;
 
-    const audioUrl = apiClient.getAudioUrl(generationId);
+    const audioUrl = versionId
+      ? apiClient.getVersionAudioUrl(versionId)
+      : apiClient.getAudioUrl(generationId);
     wavesurfer.load(audioUrl).catch(() => {
       // Ignore load errors
     });
@@ -88,7 +101,7 @@ function ClipWaveform({
       wavesurfer.destroy();
       wavesurferRef.current = null;
     };
-  }, [generationId, fullWaveformWidth]);
+  }, [generationId, versionId, fullWaveformWidth]);
 
   return (
     <div className="w-full h-full opacity-60 overflow-hidden">
@@ -135,12 +148,57 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
   const splitItem = useSplitStoryItem();
   const duplicateItem = useDuplicateStoryItem();
   const removeItem = useRemoveStoryItem();
+  const setItemVersion = useSetStoryItemVersion();
   const { toast } = useToast();
 
   // Selection state
   const selectedClipId = useStoryStore((state) => state.selectedClipId);
   const setSelectedClipId = useStoryStore((state) => state.setSelectedClipId);
 
+  // Selected clip item (for version picker)
+  const selectedItem = useMemo(
+    () => (selectedClipId ? items.find((i) => i.id === selectedClipId) : undefined),
+    [selectedClipId, items],
+  );
+  const selectedItemVersions = selectedItem?.versions;
+  const hasMultipleVersions = selectedItemVersions && selectedItemVersions.length > 1;
+
+  // Determine which version label is active for the selected clip
+  const activeVersionLabel = useMemo(() => {
+    if (!selectedItem || !selectedItemVersions) return null;
+    // If the item has a pinned version_id, find its label
+    if (selectedItem.version_id) {
+      const pinned = selectedItemVersions.find((v) => v.id === selectedItem.version_id);
+      return pinned?.label ?? null;
+    }
+    // Otherwise use the generation's default version
+    const defaultVersion = selectedItemVersions.find((v) => v.is_default);
+    return defaultVersion?.label ?? null;
+  }, [selectedItem, selectedItemVersions]);
+
+  const handleSetVersion = useCallback(
+    (versionId: string | null) => {
+      if (!selectedClipId) return;
+      setItemVersion.mutate(
+        {
+          storyId,
+          itemId: selectedClipId,
+          data: { version_id: versionId },
+        },
+        {
+          onError: (error) => {
+            toast({
+              title: 'Failed to set version',
+              description: error instanceof Error ? error.message : String(error),
+              variant: 'destructive',
+            });
+          },
+        },
+      );
+    },
+    [selectedClipId, storyId, setItemVersion, toast],
+  );
+
   // Trim state
   const [trimmingItem, setTrimmingItem] = useState<string | null>(null);
   const [trimSide, setTrimSide] = useState<'start' | 'end' | null>(null);
@@ -788,6 +846,49 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
               >
                 <Trash2 className="h-4 w-4" />
               </Button>
+              {hasMultipleVersions && (
+                <>
+                  <div className="w-px h-4 bg-border mx-1" />
+                  <DropdownMenu>
+                    <DropdownMenuTrigger asChild>
+                      <Button
+                        variant="ghost"
+                        className="h-7 gap-1.5 px-2 text-xs"
+                        title="Change version/take"
+                      >
+                        <GalleryVerticalEnd className="h-3.5 w-3.5" />
+                        <span className="max-w-[80px] truncate">
+                          {activeVersionLabel ?? 'default'}
+                        </span>
+                      </Button>
+                    </DropdownMenuTrigger>
+                    <DropdownMenuContent align="center" className="min-w-[160px]">
+                      {selectedItemVersions.map((version) => {
+                        const isActive = selectedItem?.version_id
+                          ? version.id === selectedItem.version_id
+                          : version.is_default;
+                        return (
+                          <DropdownMenuItem
+                            key={version.id}
+                            onClick={() => handleSetVersion(version.id)}
+                            className="gap-2 text-xs"
+                          >
+                            <Check
+                              className={cn('h-3 w-3', isActive ? 'opacity-100' : 'opacity-0')}
+                            />
+                            <span className="truncate">{version.label}</span>
+                            {version.effects_chain && version.effects_chain.length > 0 && (
+                              <span className="text-muted-foreground ml-auto text-[10px]">
+                                {version.effects_chain.length} fx
+                              </span>
+                            )}
+                          </DropdownMenuItem>
+                        );
+                      })}
+                    </DropdownMenuContent>
+                  </DropdownMenu>
+                </>
+              )}
             </div>
           )}
 
@@ -958,6 +1059,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
                       <div className="absolute inset-0 top-3">
                         <ClipWaveform
                           generationId={item.generation_id}
+                          versionId={item.version_id}
                           width={clipWidth}
                           trimStartMs={displayTrimStart}
                           trimEndMs={displayTrimEnd}