refactor(core): 扫清 v0.1 Phase A 技术债

- 修复测试编译回归：补全 session.rs/cycle.rs 测试模块导入；
convert.rs 2 处 irrefutable if let 改为 let
- composer.rs 迁移至 IR：OpenaiChatMessage → Message，
ContentField/OpenaiContentPart → ContentBlock；删除 set_message_name
和 build_request；developer 消息映射为 Message::System
- knowledge.rs 锁修复：std::sync::Mutex → tokio::sync::Mutex；
search() 优化锁粒度（锁内仅 clone IDs，避免锁内异步 IO）
- 标记 ChatResponse / ToolDefinition 为废弃（#[deprecated(since = "0.1.0")]），
内部使用点加 #[allow(deprecated)] 抑制警告
- clippy 清零：合并冗余 if、手动 strip_prefix 改 strip_prefix、
多处 dead_code 抑制、测试代码清理

src/memory/conversation.rs

@@ -236,7 +236,7 @@ mod tests {
         };
         let mut conv = ConversationMemory::new(store, "s1", config);
         for i in 0..5 {
-            conv.add_message(Message::user_text(&format!("msg-{i}")))
+            conv.add_message(Message::user_text(format!("msg-{i}")))
                 .await
                 .unwrap();
         }
@@ -253,7 +253,7 @@ mod tests {
         };
         let mut conv = ConversationMemory::new(store, "s1", config);
         for i in 0..5 {
-            conv.add_message(Message::user_text(&format!("msg-{i}")))
+            conv.add_message(Message::user_text(format!("msg-{i}")))
                 .await
                 .unwrap();
         }

src/memory/knowledge.rs

@@ -19,7 +19,7 @@ pub const KNOWLEDGE_PREFIX: &str = "knowledge_";
 /// 同时维护一个 `Vec<PageIndexEntry>` 索引以加速列表遍历。
 pub struct KnowledgeStore {
     store: Arc<dyn MemoryStore>,
-    index: std::sync::Mutex<Vec<PageIndexEntry>>,
+    index: tokio::sync::Mutex<Vec<PageIndexEntry>>,
 }
 
 impl KnowledgeStore {
@@ -27,7 +27,7 @@ impl KnowledgeStore {
     pub fn new(store: Arc<dyn MemoryStore>) -> Self {
         Self {
             store,
-            index: std::sync::Mutex::new(Vec::new()),
+            index: tokio::sync::Mutex::new(Vec::new()),
         }
     }
 
@@ -40,7 +40,7 @@ impl KnowledgeStore {
                 ..Default::default()
             })
             .await?;
-        let mut index = self.index.lock().unwrap();
+        let mut index = self.index.lock().await;
         index.clear();
         for item in items {
             let page: KnowledgePage = serde_json::from_str(&item.content)
@@ -66,7 +66,7 @@ impl KnowledgeStore {
             created_at: now,
         };
         self.store.save(item).await?;
-        let mut index = self.index.lock().unwrap();
+        let mut index = self.index.lock().await;
         // 替换或追加
         if let Some(existing) = index.iter_mut().find(|e| e.id == page.id) {
             *existing = PageIndexEntry::from(&page);
@@ -106,7 +106,7 @@ impl KnowledgeStore {
     pub async fn delete_page(&self, id: &str) -> Result<(), MemoryError> {
         let full_id = format!("{KNOWLEDGE_PREFIX}{id}");
         self.store.delete(&full_id).await?;
-        let mut index = self.index.lock().unwrap();
+        let mut index = self.index.lock().await;
         index.retain(|e| e.id != id);
         Ok(())
     }
@@ -120,22 +120,31 @@ impl KnowledgeStore {
             return Ok(Vec::new());
         }
         let needle = query.to_lowercase();
+        // 锁内仅 clone 匹配的 entry id，避免异步 get_page() 持有 index 锁。
+        let ids: Vec<String> = {
+            let index = self.index.lock().await;
+            index
+                .iter()
+                .filter(|entry| {
+                    entry.title.to_lowercase().contains(&needle)
+                        || entry.summary.to_lowercase().contains(&needle)
+                        || entry.tags.iter().any(|t| t.to_lowercase().contains(&needle))
+                })
+                .map(|entry| entry.id.clone())
+                .collect()
+        };
         let mut results = Vec::new();
-        let index = self.index.lock().unwrap();
-        for entry in index.iter() {
-            if (entry.title.to_lowercase().contains(&needle)
-                || entry.summary.to_lowercase().contains(&needle)
-                || entry.tags.iter().any(|t| t.to_lowercase().contains(&needle)))
-                && let Some(page) = self.get_page(&entry.id).await? {
-                    results.push(page);
-                }
+        for id in &ids {
+            if let Some(page) = self.get_page(id).await? {
+                results.push(page);
+            }
         }
         Ok(results)
     }
 
     /// 获取内容目录（所有页面的轻量级索引条目）。
-    pub fn get_index(&self) -> Vec<PageIndexEntry> {
-        self.index.lock().unwrap().clone()
+    pub async fn get_index(&self) -> Vec<PageIndexEntry> {
+        self.index.lock().await.clone()
     }
 }
 
@@ -222,7 +231,7 @@ mod tests {
         let ks = KnowledgeStore::new(store);
         ks.add_page(make_page("p1", "A", &[])).await.unwrap();
         ks.add_page(make_page("p2", "B", &[])).await.unwrap();
-        let index = ks.get_index();
+        let index = ks.get_index().await;
         assert_eq!(index.len(), 2);
     }
 
@@ -233,13 +242,13 @@ mod tests {
         // 添加页面
         ks.add_page(make_page("p1", "A", &[])).await.unwrap();
         ks.add_page(make_page("p2", "B", &[])).await.unwrap();
-        assert_eq!(ks.get_index().len(), 2);
+        assert_eq!(ks.get_index().await.len(), 2);
 
         // 模拟 index 漂移：清空后重建
-        ks.index.lock().unwrap().clear();
-        assert_eq!(ks.get_index().len(), 0);
+        ks.index.lock().await.clear();
+        assert_eq!(ks.get_index().await.len(), 0);
 
         ks.rebuild_index().await.unwrap();
-        assert_eq!(ks.get_index().len(), 2);
+        assert_eq!(ks.get_index().await.len(), 2);
     }
 }

src/memory/retriever.rs

@@ -113,9 +113,7 @@ fn extract_keywords(query: &str, stop_words: &HashSet<String>) -> Vec<String> {
         .split(|c: char| !c.is_alphanumeric())
         .filter_map(|s| {
             let lower = s.to_lowercase();
-            if lower.is_empty() || lower.chars().count() < 2 {
-                None
-            } else if stop_words.contains(&lower) {
+            if lower.is_empty() || lower.chars().count() < 2 || stop_words.contains(&lower) {
                 None
             } else {
                 Some(lower)