fix: address code review findings across undo/redo, video wiring, and validation

- Fix redo shortcut by normalizing event.key to lowercase (Shift makes it "Z")
- Flush pendingDataSnapshot in undo/redo instead of discarding it, preserving
  the pre-edit checkpoint so Cmd+Z doesn't skip states
- Recompute dimmedNodeIds after undo/redo to keep dimming in sync
- Set deleteCheckpointActive in removeEdge before clearStaleInputImages to
  prevent split undo entries
- Wire videoInput in handleMenuSelect and isValidConnection for video connections
- Validate video MIME type against ACCEPTED_FORMATS whitelist instead of broad regex
- Use URL.createObjectURL(file) for metadata extraction instead of base64→Blob
- Add Shift+Y (Video Input) to keyboard shortcuts dialog
- Update executeNode JSDoc to include videoInput as data-source no-op
- Clear all *Ref/*Refs fields dynamically in clearNodeImageRefs

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

src/components/KeyboardShortcutsDialog.tsx

@@ -37,6 +37,7 @@ const shortcutGroups: ShortcutGroup[] = [
       { keys: ["Shift", "L"], description: "Add LLM Text node" },
       { keys: ["Shift", "A"], description: "Add Annotation node" },
       { keys: ["Shift", "T"], description: "Add Audio node" },
+      { keys: ["Shift", "Y"], description: "Add Video Input node" },
       { keys: ["Shift", "R"], description: "Add Array node" },
     ],
   },

src/components/WorkflowCanvas.tsx

@@ -535,7 +535,7 @@ export function WorkflowCanvas() {
         if (!targetNode) return false;
 
         const targetNodeType = targetNode.type;
-        if (targetNodeType === "generateVideo" || targetNodeType === "videoStitch" || targetNodeType === "easeCurve" || targetNodeType === "videoTrim" || targetNodeType === "videoFrameGrab" || targetNodeType === "output" || targetNodeType === "router") {
+        if (targetNodeType === "generateVideo" || targetNodeType === "videoStitch" || targetNodeType === "easeCurve" || targetNodeType === "videoTrim" || targetNodeType === "videoFrameGrab" || targetNodeType === "videoInput" || targetNodeType === "output" || targetNodeType === "router") {
           // For output node, we allow video even though its handle is typed as "image"
           // because output node can display both images and videos
           return true;
@@ -1172,7 +1172,11 @@ export function WorkflowCanvas() {
           sourceHandleIdForNewNode = "text";
         }
       } else if (handleType === "video") {
-        if (nodeType === "videoStitch") {
+        if (nodeType === "videoInput") {
+          // VideoInput accepts video input and outputs video
+          targetHandleId = "video";
+          sourceHandleIdForNewNode = "video";
+        } else if (nodeType === "videoStitch") {
           // VideoStitch has dynamic video-N inputs and a video output
           targetHandleId = "video-0";
           sourceHandleIdForNewNode = "video";
@@ -1420,17 +1424,15 @@ export function WorkflowCanvas() {
       return;
     }
 
-    // Handle undo (Ctrl/Cmd + Z)
-    if ((event.ctrlKey || event.metaKey) && event.key === "z" && !event.shiftKey) {
+    // Handle undo (Ctrl/Cmd + Z) and redo (Ctrl/Cmd + Shift + Z)
+    // Normalize key to lowercase — Shift makes event.key uppercase ("Z" instead of "z")
+    if ((event.ctrlKey || event.metaKey) && event.key.toLowerCase() === "z") {
       event.preventDefault();
-      undo();
-      return;
-    }
-
-    // Handle redo (Ctrl/Cmd + Shift + Z)
-    if ((event.ctrlKey || event.metaKey) && event.key === "z" && event.shiftKey) {
-      event.preventDefault();
-      redo();
+      if (event.shiftKey) {
+        redo();
+      } else {
+        undo();
+      }
       return;
     }
 

src/components/nodes/VideoInputNode.tsx

@@ -11,6 +11,7 @@ type VideoInputNodeType = Node<VideoInputNodeData, "videoInput">;
 
 const MAX_FILE_SIZE = 200 * 1024 * 1024; // 200MB
 const ACCEPTED_FORMATS = "video/mp4,video/webm,video/quicktime";
+const ACCEPTED_MIME_TYPES = ACCEPTED_FORMATS.split(",");
 
 function formatDuration(seconds: number): string {
   const mins = Math.floor(seconds / 60);
@@ -31,7 +32,7 @@ export function VideoInputNode({ id, data, selected }: NodeProps<VideoInputNodeT
       const file = e.target.files?.[0];
       if (!file) return;
 
-      if (!file.type.match(/^video\//)) {
+      if (!ACCEPTED_MIME_TYPES.includes(file.type)) {
         alert("Unsupported format. Use MP4, WebM, or QuickTime video files.");
         return;
       }
@@ -41,13 +42,15 @@ export function VideoInputNode({ id, data, selected }: NodeProps<VideoInputNodeT
         return;
       }
 
+      // Extract metadata using a temporary video element pointing at the original file
+      const metadataUrl = URL.createObjectURL(file);
+      const video = document.createElement("video");
+      video.preload = "metadata";
+
       const reader = new FileReader();
       reader.onload = (event) => {
         const base64 = event.target?.result as string;
 
-        // Extract duration and dimensions using HTML Video element
-        const video = document.createElement("video");
-        video.preload = "metadata";
         video.onloadedmetadata = () => {
           updateNodeData(id, {
             video: base64,
@@ -57,7 +60,7 @@ export function VideoInputNode({ id, data, selected }: NodeProps<VideoInputNodeT
             duration: video.duration,
             dimensions: { width: video.videoWidth, height: video.videoHeight },
           });
-          URL.revokeObjectURL(video.src);
+          URL.revokeObjectURL(metadataUrl);
         };
         video.onerror = () => {
           // Still load the file even if metadata extraction fails
@@ -69,11 +72,9 @@ export function VideoInputNode({ id, data, selected }: NodeProps<VideoInputNodeT
             duration: null,
             dimensions: null,
           });
-          URL.revokeObjectURL(video.src);
+          URL.revokeObjectURL(metadataUrl);
         };
-        // Use blob URL for metadata extraction to avoid base64 parsing overhead
-        const blob = new Blob([Uint8Array.from(atob(base64.split(",")[1]), c => c.charCodeAt(0))], { type: file.type });
-        video.src = URL.createObjectURL(blob);
+        video.src = metadataUrl;
       };
       reader.readAsDataURL(file);
     },

src/store/execution/executeNode.ts

@@ -33,7 +33,7 @@ export interface ExecuteNodeOptions {
 /**
  * Execute a single node by dispatching to the appropriate executor.
  *
- * Data-source node types (`imageInput`, `audioInput`) are no-ops.
+ * Data-source node types (`imageInput`, `audioInput`, `videoInput`) are no-ops.
  */
 export async function executeNode(
   ctx: NodeExecutionContext,

src/store/utils/executionUtils.ts

@@ -129,12 +129,12 @@ export function clearNodeImageRefs(nodes: WorkflowNode[]): WorkflowNode[] {
     revokeBlobUrl(data.outputVideo as string | undefined);
     revokeBlobUrl(data.glbUrl as string | undefined);
 
-    // Clear all ref fields regardless of node type
-    delete data.imageRef;
-    delete data.sourceImageRef;
-    delete data.outputImageRef;
-    delete data.inputImageRefs;
-    delete data.videoRef;
+    // Clear all ref fields regardless of node type (match any key ending in Ref or Refs)
+    for (const key of Object.keys(data)) {
+      if (/Refs?$/.test(key)) {
+        delete data[key];
+      }
+    }
 
     return { ...node, data: data as WorkflowNodeData } as WorkflowNode;
   });

src/store/workflowStore.ts

@@ -579,8 +579,9 @@ const workflowStoreImpl: StateCreator<WorkflowStore> = (set, get) => ({
   canRedo: false,
 
   undo: () => {
-    // Discard any pending debounced data snapshot — it's intermediate state
+    // Flush any pending debounced data snapshot so the pre-edit state is preserved
     if (pendingDataSnapshot) {
+      undoManager.push(pendingDataSnapshot);
       pendingDataSnapshot = null;
       if (dataChangeTimer) {
         clearTimeout(dataChangeTimer);
@@ -597,13 +598,15 @@ const workflowStoreImpl: StateCreator<WorkflowStore> = (set, get) => ({
         edgeStyle: previous.edgeStyle,
         hasUnsavedChanges: true,
       });
+      get().recomputeDimmedNodes();
     }
     syncUndoFlags(set);
   },
 
   redo: () => {
-    // Discard any pending debounced data snapshot
+    // Flush any pending debounced data snapshot so the pre-edit state is preserved
     if (pendingDataSnapshot) {
+      undoManager.push(pendingDataSnapshot);
       pendingDataSnapshot = null;
       if (dataChangeTimer) {
         clearTimeout(dataChangeTimer);
@@ -620,6 +623,7 @@ const workflowStoreImpl: StateCreator<WorkflowStore> = (set, get) => ({
         edgeStyle: next.edgeStyle,
         hasUnsavedChanges: true,
       });
+      get().recomputeDimmedNodes();
     }
     syncUndoFlags(set);
   },
@@ -861,7 +865,14 @@ const workflowStoreImpl: StateCreator<WorkflowStore> = (set, get) => ({
       edges: state.edges.filter((edge) => edge.id !== edgeId),
       hasUnsavedChanges: true,
     }));
-    if (removedEdge) clearStaleInputImages([removedEdge], get);
+    if (removedEdge) {
+      deleteCheckpointActive = true;
+      try {
+        clearStaleInputImages([removedEdge], get);
+      } finally {
+        deleteCheckpointActive = false;
+      }
+    }
     get().incrementManualChangeCount();
   },