scaffold backup dirs at startup, ensure_dir helper

src/config.rs

@@ -55,6 +55,11 @@ pub fn backups_config_dir() -> PathBuf {
     p
 }
 
+/// Ensure a directory exists, creating all parents as needed.
+pub fn ensure_dir(path: PathBuf) {
+    let _ = std::fs::create_dir_all(&path);
+}
+
 /// Return the directory containing the running executable.
 pub fn exe_dir() -> PathBuf {
     std::env::current_exe()

src/main.rs

@@ -156,6 +156,10 @@ fn run_app<B: Backend>(terminal: &mut Terminal<B>) -> Result<()> {
          result in incomplete, corrupt, or overwritten save files.",
     )?;
 
+    // Scaffold backup directory structure
+    crate::config::ensure_dir(crate::config::backups_saves_dir());
+    crate::config::ensure_dir(crate::config::backups_config_dir());
+
     // Migrate old transaction.log into logs/ directory
     if guard::migrate_old_log() {
         guard::log_action("MIGRATE", "old transaction.log moved to logs/", "OK", &app.log_path)?;