fix(canvas): 画布同步 - 素材缺失时可强制覆盖并恢复文本与连线顺序

云端缺少素材时可用本地版强制覆盖，只清失效媒体引用。文本节点不再把资源地址当正文，合并时保留引用槽位顺序。

web/test/agent-canvas-patch.test.ts

@@ -44,6 +44,32 @@ test("new nodes and reference connections are applied atomically", () => {
     expect(result.connections).toEqual([edge]);
 });
 
+test("Agent refresh applies server reference order when local connections were untouched", () => {
+    const imageOne = { id: "image-one", fromNodeId: "image-one", toNodeId: node.id };
+    const imageTwo = { id: "image-two", fromNodeId: "image-two", toNodeId: node.id };
+    const characterOne = { id: "character-one", fromNodeId: "character-one", toNodeId: node.id };
+    const characterTwo = { id: "character-two", fromNodeId: "character-two", toNodeId: node.id };
+    const previous = { ...project, connections: [characterOne, characterTwo, imageOne, imageTwo] };
+    const incoming = { ...previous, revision: 2, connections: [imageOne, imageTwo, characterOne, characterTwo] };
+    const merged = mergeAgentCanvasEditor(previous, incoming, previous.nodes, previous.connections, previous);
+
+    expect(merged.connections.map((connection) => connection.id)).toEqual(["image-one", "image-two", "character-one", "character-two"]);
+});
+
+test("Agent refresh preserves moving the first reference to the fifth position locally", () => {
+    const roleOne = { id: "role-one", fromNodeId: "role-one", toNodeId: node.id };
+    const imageTwo = { id: "image-two", fromNodeId: "image-two", toNodeId: node.id };
+    const roleThree = { id: "role-three", fromNodeId: "role-three", toNodeId: node.id };
+    const imageFour = { id: "image-four", fromNodeId: "image-four", toNodeId: node.id };
+    const imageFive = { id: "image-five", fromNodeId: "image-five", toNodeId: node.id };
+    const previous = { ...project, connections: [roleOne, imageTwo, roleThree, imageFour, imageFive] };
+    const incoming = { ...previous, revision: 2, connections: [imageFive, roleOne, imageTwo, roleThree, imageFour] };
+    const local = { ...previous, connections: [imageTwo, roleThree, imageFour, imageFive, roleOne] };
+    const merged = mergeAgentCanvasEditor(previous, incoming, local.nodes, local.connections, local);
+
+    expect(merged.connections.map((connection) => connection.id)).toEqual(["image-two", "role-three", "image-four", "image-five", "role-one"]);
+});
+
 test("deleted nodes and a newer task binding are not overwritten", () => {
     expect(() => applyAgentCanvasPatch({ ...project, nodes: [] }, patch)).toThrow("冲突");
     // A replacement task can have the same running status; its task identity is a fence.

web/test/canvas-missing-resources.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, test } from "bun:test";
+
+import { canvasResourceIds, clearMissingCanvasResources } from "@/services/canvas-missing-resources";
+
+describe("canvas missing resource overwrite", () => {
+    test("collects nested resource locators without treating prompt text as media", () => {
+        const value = {
+            nodes: [{ id: "node-1", metadata: { storageKey: "resource:gone", prompt: "resource:keep-as-text", videoPreview: { url: "/api/resources/poster/file" } } }],
+        };
+        expect(canvasResourceIds(value)).toEqual(new Set(["gone", "poster"]));
+    });
+
+    test("removes only invalid media fields and asset binding while keeping node content", () => {
+        const value = {
+            id: "canvas",
+            nodes: [{ id: "node-1", type: "image", metadata: { assetId: "asset-1", storageKey: "resource:gone", content: "/api/resources/gone/file", prompt: "keep this prompt", status: "success" } }],
+            timeline: { clips: [{ id: "clip", directMedia: { kind: "image", assetId: "asset-1", storageKey: "resource:gone", url: "/api/resources/gone/file" } }] },
+        };
+        const repaired = clearMissingCanvasResources(value, new Set(["gone"]));
+        expect(repaired).toEqual({
+            id: "canvas",
+            nodes: [{ id: "node-1", type: "image", metadata: { prompt: "keep this prompt", status: "idle" } }],
+            timeline: { clips: [{ id: "clip", directMedia: { kind: "image" } }] },
+        });
+    });
+
+    test("server reported locator fields are also cleared during the fallback", () => {
+        const value = { nodes: [{ id: "node-1", metadata: { assetId: "asset-1", futureLocator: "resource:gone", prompt: "keep" } }] };
+        expect(clearMissingCanvasResources(value, new Set(["gone"]), "", true)).toEqual({
+            nodes: [{ id: "node-1", metadata: { assetId: "asset-1", prompt: "keep" } }],
+        });
+    });
+});

web/test/user-data-sync-media.test.ts

@@ -0,0 +1,67 @@
+import { describe, expect, test } from "bun:test";
+
+import { ensureRemoteResourceReferences, restoreRemoteTextNodeContents } from "@/services/user-data-sync-media";
+
+describe("画布资源引用同步", () => {
+    test("文本节点保留正文，只同步资源定位键", async () => {
+        const node = {
+            type: "text",
+            metadata: {
+                content: "这是上传文件的正文",
+                prompt: "这是上传文件的正文",
+                storageKey: "resource:text-file",
+                mimeType: "text/plain",
+            },
+        };
+
+        const synced = await ensureRemoteResourceReferences(node);
+
+        expect(synced.metadata.content).toBe(node.metadata.content);
+        expect(synced.metadata.prompt).toBe(node.metadata.prompt);
+        expect(synced.metadata.storageKey).toBe("resource:text-file");
+    });
+
+    test("媒体节点仍将展示字段转换为资源地址", async () => {
+        const node = {
+            type: "image",
+            metadata: {
+                content: "blob:image",
+                storageKey: "resource:image-file",
+            },
+        };
+
+        const synced = await ensureRemoteResourceReferences(node);
+
+        expect(synced.metadata.content).toContain("/resources/image-file/file");
+    });
+
+    test("加载旧画布时恢复已被保存成资源 URL 的文本正文", async () => {
+        const project = {
+            nodes: [
+                {
+                    type: "text",
+                    metadata: {
+                        content: "/api/resources/text-file/file",
+                        prompt: "上传文件的原始正文",
+                        storageKey: "resource:text-file",
+                    },
+                },
+            ],
+        };
+
+        const restored = await restoreRemoteTextNodeContents(project, async () => null);
+
+        expect(restored.nodes[0].metadata.content).toBe("上传文件的原始正文");
+    });
+
+    test("没有可恢复的 prompt 时从资源文件读取正文", async () => {
+        const project = {
+            nodes: [{ type: "text", metadata: { content: "/api/resources/text-file/file", storageKey: "resource:text-file" } }],
+        };
+
+        const restored = await restoreRemoteTextNodeContents(project, async () => "从资源恢复的正文");
+
+        expect(restored.nodes[0].metadata.content).toBe("从资源恢复的正文");
+        expect(restored.nodes[0].metadata.prompt).toBe("从资源恢复的正文");
+    });
+});