feat: 上下文压缩支持状态持久化缓存,前端过滤隐藏消息

- summarization_middleware 摘要缓存写入 LangGraph thread state,跨进程/重启可复用
- 摘要消息改为 SystemMessage,提示模型静默使用、不泄露
- thread_state 新增 context_summary_cache 字段
- app_config 加载时记录 summarization 配置日志
- config.yaml 压缩触发/保留阈值调整为生产值(token 预算)
- 前端 input-box / message-list 过滤 hide_from_ui 消息

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/components/workspace/input-box.tsx

@@ -61,8 +61,9 @@ import {
 } from "@/components/ui/dropdown-menu";
 import { apiFetch } from "@/core/api";
 import { getBackendBaseURL } from "@/core/config";
-import { useI18n } from "@/core/i18n/hooks";
-import { useModels } from "@/core/models/hooks";
+import { useI18n } from "@/core/i18n/hooks";
+import { isHiddenFromUIMessage } from "@/core/messages/utils";
+import { useModels } from "@/core/models/hooks";
 import type { AgentThreadContext } from "@/core/threads";
 import { textOfMessage } from "@/core/threads/utils";
 import { desensitize } from "@/lib/desensitize";
@@ -467,14 +468,15 @@ export function InputBox({
       return;
     }
 
-    const lastAi = [...thread.messages].reverse().find((m) => m.type === "ai");
+    const visibleMessages = thread.messages.filter((m) => !isHiddenFromUIMessage(m));
+    const lastAi = [...visibleMessages].reverse().find((m) => m.type === "ai");
     const lastAiId = lastAi?.id ?? null;
     if (!lastAiId || lastAiId === lastGeneratedForAiIdRef.current) {
       return;
     }
     lastGeneratedForAiIdRef.current = lastAiId;
 
-    const recent = thread.messages
+    const recent = visibleMessages
       .filter((m) => m.type === "human" || m.type === "ai")
       .map((m) => {
         const role = m.type === "human" ? "user" : "assistant";

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

@@ -20,9 +20,10 @@ import {
   groupMessages,
   hasContent,
   hasPresentFiles,
-  hasReasoning,
-  hasToolCalls,
-} from "@/core/messages/utils";
+  hasReasoning,
+  hasToolCalls,
+  isHiddenFromUIMessage,
+} from "@/core/messages/utils";
 import { useRehypeSplitWordsIntoSpans } from "@/core/rehype";
 import { isThreadRagModeLocked, useLocalSettings } from "@/core/settings";
 import { useSkills } from "@/core/skills/hooks";
@@ -151,7 +152,10 @@ export function MessageList({
     });
   }, []);
 
-  const allMessages = thread.messages;
+  const allMessages = useMemo(
+    () => thread.messages.filter((m) => !isHiddenFromUIMessage(m)),
+    [thread.messages],
+  );
   const messages = useMemo(
     () =>
       hiddenMessageIds.size === 0