fix: LLM 工具循环 400、中断消息注入、ConPTY 终端支持

- agent: 工具轮请求尾部补 user 占位(zen 网关强制),tool 消息正确配对
- agent: 工具提醒/中断以 system 角色注入并带 [中断消息] 前缀,不进用户履历;系统提示词说明中断消息格式
- agentcli: 基于 ConPTY 的交互式终端(ptywin fork),terminal_create/read/write/resize/close/watch
- webui: server 输出通道适配器(保留 reasoning_content/disable_thinking)
- GUI: 沉浸式标题栏、icon 圆角重制、mascot 等打磨

internal/memory/document/document.go

@@ -183,6 +183,10 @@ func (s *Store) ContextToDoc(source string, entries []ContextEntry, vec vector.V
 		docVec = vec.Vectorize(summary + " " + content)
 	} else {
 		docVec = s.veczer.Vectorize(summary + " " + content)
+	}
+		meta := map[string]string{"content_hash": contentHash}
+	if source == "context_archived" {
+		meta["is_archived_context"] = "true"
 	}
 	doc := &Doc{
 		ID:          id,
@@ -195,7 +199,7 @@ func (s *Store) ContextToDoc(source string, entries []ContextEntry, vec vector.V
 		LastAccess:  time.Now(),
 		AccessCount: 1,
 		Source:      source,
-		Meta:        map[string]string{"content_hash": contentHash},
+		Meta:        meta,
 		Vector:      docVec,
 	}
 	s.docs[id] = doc