feat: 更新记忆工具使用说明，增加高价值场景记录要求；优化技能索引提示格式，支持 XML 标记

Co-authored-by: Copilot <copilot@github.com>

src/agent/memory_tool_usage_system_prompt.md

@@ -43,7 +43,7 @@
 - 优先调用 memory_manage(action='put')；同一 namespace/key 可直接覆盖更新。
 
 
-### 以下场景视为高价值加分
+### 以下场景视为高价值加分，必须记录记忆
 - 用户多次跟你交互去优化输出
 - 用户对你的纠正
 - 确定的事实，路径/地址/网址等

src/channels/wechat.rs

@@ -160,6 +160,12 @@ impl WechatChannel {
             .map(ToOwned::to_owned);
         Ok(vec![media_item])
     }
+
+    async fn send_typing_indicator(bot: Arc<WeChatBot>, chat_id: &str) {
+        if let Err(error) = bot.send_typing(chat_id).await {
+            tracing::debug!(chat_id = %chat_id, error = %error, "Failed to send WeChat typing indicator");
+        }
+    }
 }
 
 #[async_trait]
@@ -202,6 +208,8 @@ impl Channel for WechatChannel {
                 let bot = bot_for_handler.clone();
                 let channel_name_for_publish = channel_name.clone();
                 tokio::spawn(async move {
+                    Self::send_typing_indicator(bot.clone(), &sender_id).await;
+
                     let media = match Self::download_inbound_media(bot, msg.clone()).await {
                         Ok(media) => media,
                         Err(error) => {

src/skills/mod.rs

@@ -429,18 +429,25 @@ impl SkillCatalog {
         }
 
         let mut prompt = String::from(
-            "You have access to skills discovered from local skill directories. Use a skill only when the user's request clearly matches the skill description.\nSkills are not tools. Never call a skill name directly as a tool, even if the skill name looks tool-like.\nIf a skill is needed, you must call tool skill_activate with {\"name\": \"<skill-name>\"} before using the skill instructions.\nDo not call <skill-name> directly. Always call skill_activate first.\nAvailable skills:\n",
+            "技能为特定任务提供专用说明和工作流。\n当任务匹配其描述时，使用 skill_activate 工具加载技能。\n技能不是工具名，即使技能名看起来像工具，也不能直接调用技能名。\n如果需要某个技能，必须先调用 tool skill_activate，并传入 {\"name\": \"<skill-name>\"}，再根据返回的技能说明执行。\n\n<available_skills>\n",
         );
 
         for skill in self.skills.iter().take(self.max_listed_skills) {
-            let line = format!("- {}: {}\n", skill.name, skill.description);
+            let entry = format!(
-            if prompt.len() + line.len() > self.max_index_chars {
+                "  <skill>\n    <name>{}</name>\n    <description>{}</description>\n    <location>{}</location>\n  </skill>\n",
-                prompt.push_str("- ... (truncated)\n");
+                xml_escape(&skill.name),
+                xml_escape(&skill.description),
+                xml_escape(&format!("file://{}", skill.path.display())),
+            );
+            if prompt.len() + entry.len() + "</available_skills>\n".len() > self.max_index_chars {
+                prompt.push_str("  <truncated>true</truncated>\n");
                 break;
             }
-            prompt.push_str(&line);
+            prompt.push_str(&entry);
         }
 
+        prompt.push_str("</available_skills>\n");
+
         Some(prompt)
     }
 
@@ -827,6 +834,13 @@ fn split_frontmatter(content: &str) -> Option<(&str, &str)> {
     Some((frontmatter, body))
 }
 
+fn xml_escape(value: &str) -> String {
+    value
+        .replace('&', "&amp;")
+        .replace('<', "&lt;")
+        .replace('>', "&gt;")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -925,6 +939,29 @@ mod tests {
         assert!(payload.contains("Step A"));
     }
 
+    #[test]
+    fn test_system_index_prompt_uses_available_skills_markup() {
+        let catalog = SkillCatalog {
+            skills: vec![Skill {
+                name: "demo-skill".to_string(),
+                description: "demo <skill> & usage".to_string(),
+                body: String::new(),
+                source: SkillSource::Project,
+                path: PathBuf::from("/tmp/demo-skill/SKILL.md"),
+            }],
+            max_index_chars: 4000,
+            max_listed_skills: 32,
+        };
+
+        let prompt = catalog.system_index_prompt().unwrap();
+        assert!(prompt.contains("<available_skills>"));
+        assert!(prompt.contains("技能为特定任务提供专用说明和工作流。"));
+        assert!(prompt.contains("<name>demo-skill</name>"));
+        assert!(prompt.contains("<description>demo &lt;skill&gt; &amp; usage</description>"));
+        assert!(prompt.contains("<location>file:///tmp/demo-skill/SKILL.md</location>"));
+        assert!(prompt.contains("</available_skills>"));
+    }
+
     #[test]
     fn test_runtime_create_update_delete_reload() {
         let _lock = acquire_test_lock();