同步封面和标题更新后的画布版本

自动封面和标题更新会推进画布版本，但页面未同步，导致后续节点保存持续冲突。元数据写入返回前一版本，客户端仅在与本地版本衔接时推进版本，并与画布保存共用队列；处理结果在合并成功后才更新本地版本。视频画布导入也按节点保存、标题更新顺序执行。

验证：17 项画布能力与同步测试通过，包含封面更新后的保存、不覆盖未同步的远端改动、结果合并冲突和切换画布；TypeScript 检查通过。

app/api/canvas/[id]/route.ts

@@ -207,7 +207,11 @@ export async function PUT(
           ),
         )
         .returning();
-      return NextResponse.json({ success: true, data: saved });
+      return NextResponse.json({
+        success: true,
+        data: saved,
+        previousCanvasRevision: existingProject?.updatedAt.toISOString() ?? null,
+      });
     });
   } catch (error) {
     console.error("更新/创建画布失败:", error);

app/canvas/[id]/CanvasEditorLegacyPageClient.tsx

@@ -3947,20 +3947,18 @@ export default function CanvasEditorLegacyPage({
         loadCanvas(normalized.canvasData);
         setProjectTitle(nextTitle);
 
-        const [saveResult, updateResult] = await Promise.all([
-          canvasService.saveCanvasState(
+        const saveResult = await canvasService.saveCanvasState(
             id,
             normalized.canvasData,
             activeCanvasWorkspaceType
-          ),
-          canvasService.updateProject(
+          );
+        const updateResult = await canvasService.updateProject(
             id,
             {
               title: nextTitle,
             },
             activeCanvasWorkspaceType
-          ),
-        ]);
+          );
 
         if (!saveResult.success) {
           throw new Error(saveResult.error || "导入后保存失败");
@@ -5350,11 +5348,11 @@ export default function CanvasEditorLegacyPage({
 
       try {
         if (autoThumbnailSyncedRef.current !== autoTitleKey) {
-          await canvasService.updateProject(
+          await canvasSaveQueue.current!.enqueue(() => canvasService.updateProject(
             id,
             { thumbnail: imageSrc },
             activeCanvasWorkspaceType
-          );
+          ));
           autoThumbnailSyncedRef.current = autoTitleKey;
         }
 
@@ -5370,11 +5368,11 @@ export default function CanvasEditorLegacyPage({
         const data = await res.json();
         if (data.title) {
           setProjectTitle(data.title);
-          await canvasService.updateProject(
+          await canvasSaveQueue.current!.enqueue(() => canvasService.updateProject(
             id,
             { title: data.title },
             activeCanvasWorkspaceType
-          );
+          ));
           toast.success(`${workspaceLabel}已自动命名为：${data.title}`);
         }
       } catch (error) {
@@ -5425,11 +5423,11 @@ export default function CanvasEditorLegacyPage({
       return;
     }
 
-    const result = await canvasService.updateProject(
+    const result = await canvasSaveQueue.current!.enqueue(() => canvasService.updateProject(
       id,
       { title: editTitle.trim() },
       activeCanvasWorkspaceType
-    );
+    ));
     if (result.success) {
       setProjectTitle(editTitle.trim());
     } else {

lib/client/canvas-toolbar-capability.ts

@@ -1,6 +1,5 @@
 import type { CanvasCapabilityClientCommand } from "@/lib/canvas/capabilities/client-command";
 import { mergeCanvasSnapshots } from "@/lib/video-canvas/merge-snapshot";
-import { canvasService } from "@/services/canvas";
 import { useCanvasStore } from "@/store/canvas";
 
 /** Runs after the editor has saved and while its save queue is reserved. */
@@ -21,8 +20,9 @@ export async function executeCanvasToolbarCapability(
     throw new Error(payload?.error || "图片处理失败");
   }
 
-  const result = await canvasService.getProject(projectId);
-  if (!result.success || !result.data?.canvasData) {
+  const projectResponse = await fetch(`/api/canvas/${projectId}`);
+  const result = await projectResponse.json();
+  if (!projectResponse.ok || !result.success || !result.data?.canvasData) {
     throw new Error(result.error || "结果已生成，但画布同步失败");
   }
   const current = useCanvasStore.getState();

services/canvas/index.ts

@@ -248,6 +248,17 @@ export const canvasService = {
         ),
       });
       const data = await response.json();
+      if (data?.success && data?.previousCanvasRevision && data?.data?.updatedAt) {
+        const current = useCanvasStore.getState();
+        // Metadata-only writes advance the same revision used by canvas saves.
+        // Adopt it only when no unseen canvas revision lies between them.
+        if (
+          current.projectId === id &&
+          current.canvasRevision === data.previousCanvasRevision
+        ) {
+          current.setCanvasRevision(String(data.data.updatedAt), String(data.data.updatedAt));
+        }
+      }
       return data;
     } catch (error) {
       return { success: false, error: '更新画布失败' };

tests/routes/canvas-toolbar-capability.test.ts

@@ -3,6 +3,7 @@ import { createCanvasSaveQueue } from "@/lib/client/canvas-save-queue";
 import { executeCanvasToolbarCapability } from "@/lib/client/canvas-toolbar-capability";
 import { createCanvasCapabilityClientCommand } from "@/lib/canvas/capabilities/client-command";
 import { useCanvasStore } from "@/store/canvas";
+import { canvasService } from "@/services/canvas";
 
 const originalFetch = globalThis.fetch;
 const node = (id: string) => ({ id, type: "image", position: { x: 0, y: 0 },
@@ -79,3 +80,37 @@ test("switching projects during processing does not load the old result into the
   expect(useCanvasStore.getState().nodes.map(n => n.id)).toEqual(["other"]);
   expect(useCanvasStore.getState().canvasRevision).toBe("r1");
 });
+
+test("cover updates advance the local revision before the next queued save", async () => {
+  const queue = createCanvasSaveQueue();
+  globalThis.fetch = (async () => Response.json({
+    success: true, previousCanvasRevision: "r1", data: { updatedAt: "r2" },
+  })) as typeof fetch;
+  const cover = queue.enqueue(() => canvasService.updateProject("project-a", { thumbnail: "https://example.com/source.png" }));
+  const nextSave = queue.enqueue(async () => useCanvasStore.getState().canvasRevision);
+  await cover;
+  expect(await nextSave).toBe("r2");
+});
+
+test("metadata changes never adopt an unseen remote canvas revision", async () => {
+  globalThis.fetch = (async () => Response.json({
+    success: true, previousCanvasRevision: "external-edit", data: { updatedAt: "r3" },
+  })) as typeof fetch;
+  await canvasService.updateProject("project-a", { title: "Renamed" });
+  expect(useCanvasStore.getState().canvasRevision).toBe("r1");
+});
+
+test("a result merge conflict retains both the local edit and its original revision", async () => {
+  globalThis.fetch = (async (url) => {
+    if (String(url).endsWith("/capabilities")) {
+      useCanvasStore.getState().moveNode("source", { x: 50, y: 80 });
+      return Response.json({ success: true });
+    }
+    return Response.json({ success: true, data: { updatedAt: "r2", canvasData: {
+      nodes: [{ ...node("source"), position: { x: 200, y: 80 } }, node("result")], edges: [],
+    } } });
+  }) as typeof fetch;
+  await expect(executeCanvasToolbarCapability(command())).rejects.toThrow("画布有冲突");
+  expect(useCanvasStore.getState().canvasRevision).toBe("r1");
+  expect(useCanvasStore.getState().nodes[0].position).toEqual({ x: 50, y: 80 });
+});