feat(storage): 创建 storage 模块骨架

src/lib.rs

@@ -10,4 +10,5 @@ pub mod channels;
 pub mod logging;
 pub mod observability;
 pub mod skills;
+pub mod storage;
 pub mod tools;

src/storage/message.rs

@@ -0,0 +1 @@
+// Message CRUD 操作占位符

src/storage/mod.rs

@@ -0,0 +1,5 @@
+pub mod error;
+pub mod session;
+pub mod message;
+
+pub use error::StorageError;

src/storage/session.rs

@@ -0,0 +1 @@
+// Session CRUD 操作占位符