技能展示样本运行器 + 参考文献来源过滤调整

- skills 路由新增 _run_skill_python_sample，按本地 Python 候选实际执行
  技能脚本，作为展示适配器的真实样本来源
- skill-display 运行时与适配器调整，参考文献收集放宽起始消息约束

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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

@@ -65,25 +65,16 @@ const ChatBox: React.FC<{ children: React.ReactNode; threadId: string }> = ({
     () => findLatestHumanMessageIndex(thread.values.messages ?? []),
     [thread.values.messages],
   );
-  const latestAssistant = useMemo(
-    () => findLatestAssistantMessageAfter(thread.values.messages ?? [], latestHumanIndex),
-    [latestHumanIndex, thread.values.messages],
-  );
   const displaySources = useMemo(() => {
     if (!settings.display.ragModeEnabled) {
       return [];
     }
     const messages = thread.values.messages ?? [];
-    if (!latestAssistant?.id) {
-      return [];
-    }
     return collectRuntimeDisplaySources(messages, skillDisplayMap, {
       afterMessageId: latestHumanIndex >= 0 ? messages[latestHumanIndex]?.id : undefined,
-      beforeMessageId: latestAssistant.id,
-      includeBeforeMessage: true,
       includeModes: ["citation"],
     });
-  }, [settings.display.ragModeEnabled, skillDisplayMap, latestAssistant?.id, latestHumanIndex, thread.values.messages]);
+  }, [settings.display.ragModeEnabled, skillDisplayMap, latestHumanIndex, thread.values.messages]);
   const referenceSources = useMemo(
     () => displaySources.filter((source) => source.mode === "citation"),
     [displaySources],
@@ -93,7 +84,7 @@ const ChatBox: React.FC<{ children: React.ReactNode; threadId: string }> = ({
     if (hasCitationReferences) {
       setReferencesOpen(true);
     }
-  }, [hasCitationReferences, latestAssistant?.id]);
+  }, [hasCitationReferences]);
   useEffect(() => {
     const handleShowReference = () => {
       setReferencesOpen(true);
@@ -333,17 +324,4 @@ function findLatestHumanMessageIndex(messages: Message[]) {
   return -1;
 }
 
-function findLatestAssistantMessageAfter(messages: Message[], afterIndex: number) {
-  for (let index = messages.length - 1; index >= 0; index--) {
-    if (afterIndex >= 0 && index <= afterIndex) {
-      return null;
-    }
-    const message = messages[index];
-    if (message?.type === "ai") {
-      return message;
-    }
-  }
-  return null;
-}
-
 export { ChatBox };