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.

tests/audio.rs

@@ -1,65 +1,65 @@
 use rodio::Decoder;
 use std::{
-  fs::{self, read},
-  io::{BufReader, Cursor},
-  path::PathBuf,
-  process::{Command, Output},
+    fs::{self, read},
+    io::{BufReader, Cursor},
+    path::PathBuf,
+    process::{Command, Output},
 };
 use war_in_tunnels::app::threads::{SoundrackParts, Soundtrack, load_audio};
 
 #[test]
 fn audio_repeats_after_end_of_file() {
-  let data = read("soundtracks/default/calm.ogg").unwrap();
-  let sample_count = Decoder::new(BufReader::new(Cursor::new(data)))
-    .unwrap()
-    .count();
-  assert!(sample_count > 0);
+    let data = read("soundtracks/default/calm.ogg").unwrap();
+    let sample_count = Decoder::new(BufReader::new(Cursor::new(data)))
+        .unwrap()
+        .count();
+    assert!(sample_count > 0);
 
-  let mut source = load_audio(&Soundtrack::Default, &SoundrackParts::Calm);
-  assert_eq!(source.by_ref().take(sample_count).count(), sample_count);
-  assert_eq!(source.take(1024).count(), 1024);
+    let mut source = load_audio(&Soundtrack::Default, &SoundrackParts::Calm);
+    assert_eq!(source.by_ref().take(sample_count).count(), sample_count);
+    assert_eq!(source.take(1024).count(), 1024);
 }
 
 #[test]
 fn packaged_audio_loads_without_project_working_directory() -> () {
-  if std::env::var_os("WAR_IN_TUNNELS_PACKAGED_AUDIO_TEST").is_some() {
-    let mut source: rodio::source::Amplify<
-      rodio::decoder::LoopedDecoder<BufReader<Cursor<Vec<u8>>>>,
-    > = load_audio(&Soundtrack::Default, &SoundrackParts::Calm);
-    assert_eq!(source.by_ref().take(1024).count(), 1024);
-    return;
-  }
+    if std::env::var_os("WAR_IN_TUNNELS_PACKAGED_AUDIO_TEST").is_some() {
+        let mut source: rodio::source::Amplify<
+            rodio::decoder::LoopedDecoder<BufReader<Cursor<Vec<u8>>>>,
+        > = load_audio(&Soundtrack::Default, &SoundrackParts::Calm);
+        assert_eq!(source.by_ref().take(1024).count(), 1024);
+        return;
+    }
 
-  let directory: PathBuf = std::env::temp_dir().join(format!(
-    "war-in-tunnels-packaged-audio-{}",
-    std::process::id()
-  ));
-  fs::create_dir_all(directory.join("soundtracks/default")).unwrap();
-  fs::create_dir_all(directory.join("working-directory")).unwrap();
-  let executable: PathBuf = directory.join("audio-test");
-  fs::copy(std::env::current_exe().unwrap(), &executable).unwrap();
-  for filename in ["calm.ogg", "test.ogg"] {
-    fs::copy(
-      PathBuf::from("soundtracks/default").join(filename),
-      directory.join("soundtracks/default").join(filename),
-    )
-    .unwrap();
-  }
-  let output: Output = Command::new(executable)
-    .args([
-      "--exact",
-      "packaged_audio_loads_without_project_working_directory",
-      "--nocapture",
-    ])
-    .env("WAR_IN_TUNNELS_PACKAGED_AUDIO_TEST", "1")
-    .current_dir(directory.join("working-directory"))
-    .output()
-    .unwrap();
-  fs::remove_dir_all(directory).unwrap();
-  assert!(
-    output.status.success(),
-    "{}{}",
-    String::from_utf8_lossy(&output.stdout),
-    String::from_utf8_lossy(&output.stderr)
-  );
+    let directory: PathBuf = std::env::temp_dir().join(format!(
+        "war-in-tunnels-packaged-audio-{}",
+        std::process::id()
+    ));
+    fs::create_dir_all(directory.join("soundtracks/default")).unwrap();
+    fs::create_dir_all(directory.join("working-directory")).unwrap();
+    let executable: PathBuf = directory.join("audio-test");
+    fs::copy(std::env::current_exe().unwrap(), &executable).unwrap();
+    for filename in ["calm.ogg", "test.ogg"] {
+        fs::copy(
+            PathBuf::from("soundtracks/default").join(filename),
+            directory.join("soundtracks/default").join(filename),
+        )
+        .unwrap();
+    }
+    let output: Output = Command::new(executable)
+        .args([
+            "--exact",
+            "packaged_audio_loads_without_project_working_directory",
+            "--nocapture",
+        ])
+        .env("WAR_IN_TUNNELS_PACKAGED_AUDIO_TEST", "1")
+        .current_dir(directory.join("working-directory"))
+        .output()
+        .unwrap();
+    fs::remove_dir_all(directory).unwrap();
+    assert!(
+        output.status.success(),
+        "{}{}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr)
+    );
 }