Refactor project structure and update .gitignore; enhance README with setup instructions and environment requirements. Clean up backend code for improved readability and maintainability.

backend/src/main/java/com/sshmanager/dto/SftpFileInfo.java

@@ -1,15 +1,15 @@
-package com.sshmanager.dto;
-
-import lombok.AllArgsConstructor;
-import lombok.Data;
-import lombok.NoArgsConstructor;
-
-@Data
-@NoArgsConstructor
-@AllArgsConstructor
-public class SftpFileInfo {
-    private String name;
-    private boolean directory;
-    private long size;
-    private long mtime;
-}
+package com.sshmanager.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class SftpFileInfo {
+    private String name;
+    private boolean directory;
+    private long size;
+    private long mtime;
+}