Remove video canvas demo shells and fix media upload timeouts

- Starter/toolbox presets no longer seed fake generated results; demo
  fallback media URLs in tool actions now fail with honest guidance
- Delete dead demo scene components, fake director console, demo
  history constants and unreachable submit toast fallbacks
- Smart edit dialog accepts desktop drag-and-drop video files
- Raise media upload client timeout to 10 minutes and surface
  friendly timeout errors instead of raw 'signal timed out'

components/canvas/smart-edit/SmartEditDialog.tsx

@@ -90,6 +90,23 @@ export function SmartEditDialog({
     [zoom, setZoom] = useState(1),
     [snap, setSnap] = useState(true);
   const [configure, setConfigure] = useState(false);
+  const [videoDragActive, setVideoDragActive] = useState(false);
+  const videoDragDepthRef = useRef(0);
+  const uploadVideoFiles = async (files: File[]) => {
+    if (!files.length) return;
+    if (files.length + draft.assets.length > 12) {
+      setError("最多 12 个素材");
+      return;
+    }
+    setBusy(true);
+    try {
+      for (const file of files) await upload(file, "video");
+    } catch (e) {
+      setError((e as Error).message);
+    } finally {
+      setBusy(false);
+    }
+  };
   const applied = useRef(planTaskId);
   useEffect(() => {
     if (planTaskId && planTaskId !== applied.current) {
@@ -112,7 +129,7 @@ export function SmartEditDialog({
     fetch("/api/canvas/smart-edit/capabilities", { signal: controller.signal })
       .then(async (r) => {
         const data = await r.json();
-        if (!r.ok) throw Error(data.error);
+        if (!r.ok) throw new Error(data.error);
         setCap(data);
       })
       .catch((e) => {
@@ -185,17 +202,26 @@ export function SmartEditDialog({
     setTimeout(() => URL.revokeObjectURL(url), 1000);
   };
   const upload = async (file: File, kind: "video" | "audio") => {
-    if (file.size > 125 * 1024 * 1024) throw Error("单个素材不得超过 125 MiB");
+    if (file.size > 125 * 1024 * 1024) throw new Error("单个素材不得超过 125 MiB");
     const form = new FormData();
     form.append("file", file);
-    const response = await fetch("/api/canvas/media/upload", {
-      method: "POST",
-      body: form,
-      signal: AbortSignal.timeout(120000),
-    });
+    let response: Response;
+    try {
+      response = await fetch("/api/canvas/media/upload", {
+        method: "POST",
+        body: form,
+        signal: AbortSignal.timeout(600000),
+      });
+    } catch (e) {
+      throw new Error(
+        e instanceof DOMException && (e.name === "TimeoutError" || e.name === "AbortError")
+          ? "上传超时，请检查网络后重试，或改用更小的素材"
+          : "上传失败，请检查网络后重试",
+      );
+    }
     const result = await response.json();
     const url = result.url || result.data?.url;
-    if (!response.ok || !url) throw Error(result.error || "上传失败");
+    if (!response.ok || !url) throw new Error(result.error || "上传失败");
     if (kind === "audio") patch({ music: { url, gain: 0.2, start: 0 } });
     else
       patch({
@@ -308,7 +334,43 @@ export function SmartEditDialog({
       aria-modal="true"
       aria-label="智能剪辑"
       className="fixed inset-0 z-[160] flex flex-col bg-[#171717] text-white"
+      onDragEnter={(e) => {
+        if (!Array.from(e.dataTransfer.types).includes("Files")) return;
+        e.preventDefault();
+        videoDragDepthRef.current += 1;
+        setVideoDragActive(true);
+      }}
+      onDragOver={(e) => {
+        if (!Array.from(e.dataTransfer.types).includes("Files")) return;
+        e.preventDefault();
+        e.dataTransfer.dropEffect = "copy";
+      }}
+      onDragLeave={(e) => {
+        videoDragDepthRef.current = Math.max(0, videoDragDepthRef.current - 1);
+        if (!videoDragDepthRef.current) setVideoDragActive(false);
+      }}
+      onDrop={(e) => {
+        if (!Array.from(e.dataTransfer.types).includes("Files")) return;
+        e.preventDefault();
+        videoDragDepthRef.current = 0;
+        setVideoDragActive(false);
+        const files = Array.from(e.dataTransfer.files).filter((file) =>
+          file.type.startsWith("video/"),
+        );
+        if (!files.length) {
+          setError("请拖入 MP4、MOV 或 WebM 视频素材");
+          return;
+        }
+        void uploadVideoFiles(files);
+      }}
     >
+      {videoDragActive ? (
+        <div className="pointer-events-none fixed inset-0 z-[300] flex items-center justify-center border-4 border-dashed border-cyan-300/70 bg-cyan-300/5">
+          <span className="rounded-lg bg-black/70 px-4 py-2 text-sm">
+            松开以上传视频素材
+          </span>
+        </div>
+      ) : null}
       <header className="flex shrink-0 items-center justify-between border-b border-white/15 px-5 py-3">
         <h2>智能剪辑 · {plan?.title || "从素材到成片"}</h2>
         {plan && (
@@ -371,18 +433,7 @@ export function SmartEditDialog({
                   onChange={async (e) => {
                     const files = Array.from(e.target.files || []);
                     e.target.value = "";
-                    if (files.length + draft.assets.length > 12) {
-                      setError("最多 12 个素材");
-                      return;
-                    }
-                    setBusy(true);
-                    try {
-                      for (const file of files) await upload(file, "video");
-                    } catch (e) {
-                      setError((e as Error).message);
-                    } finally {
-                      setBusy(false);
-                    }
+                    await uploadVideoFiles(files);
                   }}
                 />
               </label>

components/canvas/smart-edit/SmartEditNode.tsx

@@ -236,14 +236,23 @@ export function SmartEditNodeComposer({
           try {
             const body = new FormData();
             body.append("file", file);
-            const response = await fetch("/api/canvas/media/upload", {
-              method: "POST",
-              body,
-              signal: AbortSignal.timeout(120000),
-            });
+            let response: Response;
+            try {
+              response = await fetch("/api/canvas/media/upload", {
+                method: "POST",
+                body,
+                signal: AbortSignal.timeout(600000),
+              });
+            } catch (e) {
+              throw new Error(
+                e instanceof DOMException && (e.name === "TimeoutError" || e.name === "AbortError")
+                  ? "上传超时，请检查网络后重试，或改用更小的素材"
+                  : "上传失败，请检查网络后重试",
+              );
+            }
             const data = await response.json(),
               url = data.url || data.data?.url;
-            if (!response.ok || !url) throw Error(data.error || "音乐上传失败");
+            if (!response.ok || !url) throw new Error(data.error || "音乐上传失败");
             onDraft({ music: { url, gain: 0.2, start: 0 } });
           } catch (e) {
             setError(e instanceof Error ? e.message : "音乐上传失败");