Update formatting to use 4‑space indentation

- Adjust rustfmt.toml to set tab_spaces = 4.
- Reformat imports, struct definitions, function bodies, and match arms
  across the project to match the new style (aligned fields, added
  spacing, etc.).
- Ensure all code complies with the updated rustfmt settings.

src/logs.rs

@@ -28,10 +28,10 @@ use std::fs::File;
 /// }
 /// ```
 pub fn init_logger() {
-  WriteLogger::init(
-    LevelFilter::Info,
-    Config::default(),
-    File::create("war_in_tunnels.log").expect("Failed to create log file"),
-  )
-  .expect("Failed to initialize logger");
+    WriteLogger::init(
+        LevelFilter::Info,
+        Config::default(),
+        File::create("war_in_tunnels.log").expect("Failed to create log file"),
+    )
+    .expect("Failed to initialize logger");
 }