fix: writing mode first-report allows only the pipeline to write the report

- Strip write_file/str_replace/bash from the model binding in the
  first-report run: after_model rewrites only fire after a full model
  response, so any bound write tool let weak models draft the whole
  essay into tool args (write_file content or bash cat>/python
  heredocs) for tens of invisible seconds before interception
- Hallucinated hand-writes are still handled: after_model rewrites
  bash cat >/python open('w')/tee and leftover write calls to
  deep_research_report; wrap_tool_call rejects whatever reaches the
  tool layer; post-success writes are dropped, nudged to a 2-3
  sentence summary, and patched with a fallback closing message so
  the turn never ends silently
- The rewritten pipeline call carries topic = original request
  (clarification answers skipped) plus focus = clarification answers,
  so the pipeline writes the clarified subject instead of the raw
  prompt text; prompts updated to match (tools unavailable, call the
  tool directly, do not draft first)
- Frontend write-step interception and streaming preview scoping now
  applies only in writing mode; normal mode shows/previews writes
  exactly as before

frontend-web/src/components/workspace/chats/chat-box.tsx

@@ -101,6 +101,9 @@ const ChatBox: React.FC<{
   const [pinnedReferenceId, setPinnedReferenceId] = useState<string | null>(null);
   const [backendReferenceBatches, setBackendReferenceBatches] = useState<BackendReferenceBatch[]>([]);
   const [settings] = useLocalSettings();
+  // 写作模式专属的产物拦截 / 沙箱打开策略只在开关开启时生效，普通模式保持
+  // 原有行为（新产物自动打开 + in-flight 预览不过滤）。
+  const writingModeEnabled = !!settings.context.writing_mode;
   const artifactDirectoryModeEnabled =
     settings.display.artifactDirectoryModeEnabled ?? false;
   const ragModeEnabled =
@@ -392,7 +395,7 @@ const ChatBox: React.FC<{
         ((hasNewArtifact || !hadArtifacts) && !selectedArtifact))
     ) {
       const newest = nextArtifacts[nextArtifacts.length - 1]!;
-      if (shouldAutoOpenWritingArtifact(newest, thread.messages)) {
+      if (shouldAutoOpenWritingArtifact(newest, thread.messages, writingModeEnabled)) {
         selectArtifact(newest);
         setArtifactsOpen(true);
         setSideTab("document");
@@ -429,6 +432,7 @@ const ChatBox: React.FC<{
     availableArtifacts,
     disableArtifacts,
     thread.messages,
+    writingModeEnabled,
   ]);
 
   // Live sandbox: open as soon as any in-flight write_file has a path or
@@ -439,8 +443,8 @@ const ChatBox: React.FC<{
     () =>
       disableArtifacts || !thread.isLoading
         ? null
-        : latestInFlightWriteFilePreview(thread.messages ?? []),
-    [disableArtifacts, thread.isLoading, thread.messages],
+        : latestInFlightWriteFilePreview(thread.messages ?? [], writingModeEnabled),
+    [disableArtifacts, thread.isLoading, thread.messages, writingModeEnabled],
   );
   useEffect(() => {
     if (!streamingWritePreview) return;

frontend-web/src/components/workspace/messages/message-group.tsx

@@ -101,8 +101,14 @@ export function MessageGroup({
   const [showLastThinking, setShowLastThinking] = useState(
     env.NEXT_PUBLIC_STATIC_WEBSITE_ONLY === "true",
   );
-  const steps = useMemo(() => convertToSteps(messages), [messages]);
   const [settings] = useLocalSettings();
+  // 写作模式的「拦截 outputs/*.md 手写」只在写作模式生效；普通模式的
+  // write_file / read_file 步骤条必须照旧显示。
+  const writingModeEnabled = !!settings.context.writing_mode;
+  const steps = useMemo(
+    () => convertToSteps(messages, writingModeEnabled),
+    [messages, writingModeEnabled],
+  );
   const { skills } = useSkills();
   const skillDisplayMap = useMemo(
     () => (settings.display.ragModeEnabled ? buildSkillDisplayMap(skills) : new Map()),
@@ -849,7 +855,7 @@ interface CoTToolCallStep extends GenericCoTStep<"toolCall"> {
 
 type CoTStep = CoTReasoningStep | CoTToolCallStep;
 
-function convertToSteps(messages: Message[]): CoTStep[] {
+function convertToSteps(messages: Message[], writingMode: boolean): CoTStep[] {
   const steps: CoTStep[] = [];
   for (const message of messages) {
     if (message.type === "ai") {
@@ -879,7 +885,7 @@ function convertToSteps(messages: Message[]): CoTStep[] {
             tool_call.name === "read_multiple_files" ||
             tool_call.name === "present_files"
           ) &&
-          isInterceptedWritingReportWrite(writePath, message.id, messages)
+          isInterceptedWritingReportWrite(writePath, message.id, messages, writingMode)
         ) {
           continue;
         }