style: apply cargo fmt across the crate (A20)

The repo never enforced rustfmt, so formatting had drifted broadly. This is a
single mechanical `cargo fmt` pass over the whole crate (no behavioral change;
lib suite green, 493 passed). Going forward fmt should be enforced (planned CI
fmt --check step). Part of the 0.6.1 hygiene pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/game/steam.rs

@@ -25,8 +25,7 @@ const MAX_STEAM_PATH_BYTES: u32 = 4 * 1024;
 
 #[cfg(any(windows, test))]
 fn validate_reg_len(len: u32) -> Option<usize> {
-    (len != 0 && len.is_multiple_of(2) && len <= MAX_STEAM_PATH_BYTES)
-        .then_some(len as usize / 2)
+    (len != 0 && len.is_multiple_of(2) && len <= MAX_STEAM_PATH_BYTES).then_some(len as usize / 2)
 }
 
 #[cfg(any(windows, test))]
@@ -48,7 +47,14 @@ fn decode_reg_sz(mut buf: Vec<u16>, returned_bytes: u32) -> Option<String> {
 pub fn parse_running_app_id(registry_vdf: &str) -> Option<u32> {
     let root = vdf::parse(registry_vdf).ok()?;
     let raw = root
-        .get_path(&["Registry", "HKCU", "Software", "Valve", "Steam", "RunningAppID"])
+        .get_path(&[
+            "Registry",
+            "HKCU",
+            "Software",
+            "Valve",
+            "Steam",
+            "RunningAppID",
+        ])
         .and_then(Value::as_str)?;
     let id: u32 = raw.trim().parse().ok()?;
     (id != 0).then_some(id)
@@ -196,7 +202,13 @@ impl SteamProbe {
             return cached.name.clone();
         }
         let name = read_capped(&manifest).and_then(|c| parse_app_name(&c));
-        self.manifests.insert(app_id, CachedManifest { mtime, name: name.clone() });
+        self.manifests.insert(
+            app_id,
+            CachedManifest {
+                mtime,
+                name: name.clone(),
+            },
+        );
         name
     }
 
@@ -240,7 +252,11 @@ impl SteamProbe {
                 paths.push(root.clone());
             }
         }
-        self.libraries = CachedLibraries { source, mtime, paths: paths.clone() };
+        self.libraries = CachedLibraries {
+            source,
+            mtime,
+            paths: paths.clone(),
+        };
         paths
     }
 }
@@ -360,8 +376,8 @@ mod win {
     use std::path::PathBuf;
     use windows_sys::Win32::Foundation::ERROR_SUCCESS;
     use windows_sys::Win32::System::Registry::{
-        RegCloseKey, RegOpenKeyExW, RegQueryValueExW, HKEY, HKEY_CURRENT_USER, KEY_READ,
-        REG_DWORD, REG_SZ,
+        HKEY, HKEY_CURRENT_USER, KEY_READ, REG_DWORD, REG_SZ, RegCloseKey, RegOpenKeyExW,
+        RegQueryValueExW,
     };
 
     /// UTF-16, NUL-terminated, for a Win32 wide-string argument.
@@ -374,9 +390,8 @@ mod win {
         let subkey = wide("Software\\Valve\\Steam");
         let mut hkey: HKEY = std::ptr::null_mut();
         // SAFETY: valid HKEY constant, NUL-terminated subkey, out-param for the handle.
-        let rc = unsafe {
-            RegOpenKeyExW(HKEY_CURRENT_USER, subkey.as_ptr(), 0, KEY_READ, &mut hkey)
-        };
+        let rc =
+            unsafe { RegOpenKeyExW(HKEY_CURRENT_USER, subkey.as_ptr(), 0, KEY_READ, &mut hkey) };
         (rc == ERROR_SUCCESS).then_some(hkey)
     }
 
@@ -463,13 +478,20 @@ mod tests {
 
     #[test]
     fn registry_string_lengths_are_bounded_and_trimmed() {
-        assert_eq!(validate_reg_len(5), None, "odd byte lengths are invalid UTF-16");
+        assert_eq!(
+            validate_reg_len(5),
+            None,
+            "odd byte lengths are invalid UTF-16"
+        );
         assert_eq!(validate_reg_len(MAX_STEAM_PATH_BYTES + 2), None);
         assert_eq!(validate_reg_len(8), Some(4));
 
         let raw = "C:\\Steam\0ignored".encode_utf16().collect::<Vec<_>>();
         let returned_bytes = ("C:\\Steam\0".encode_utf16().count() * 2) as u32;
-        assert_eq!(decode_reg_sz(raw, returned_bytes).as_deref(), Some("C:\\Steam"));
+        assert_eq!(
+            decode_reg_sz(raw, returned_bytes).as_deref(),
+            Some("C:\\Steam")
+        );
     }
 
     #[test]
@@ -495,10 +517,13 @@ mod tests {
             "contentstatsid" "12345"
         }"#;
         let got = parse_library_paths(current);
-        assert_eq!(got, vec![
-            PathBuf::from("/home/eric/.local/share/Steam"),
-            PathBuf::from("/mnt/games/SteamLibrary"),
-        ]);
+        assert_eq!(
+            got,
+            vec![
+                PathBuf::from("/home/eric/.local/share/Steam"),
+                PathBuf::from("/mnt/games/SteamLibrary"),
+            ]
+        );
 
         // Legacy shape: numeric keys map straight to path strings.
         let legacy = r#""LibraryFolders" {
@@ -522,13 +547,25 @@ mod tests {
         let environ = b"PATH=/usr/bin\0SteamAppId=440\0HOME=/home/x\0SteamGameId=440\0";
         assert_eq!(parse_steam_app_id_from_environ(environ), Some(440));
         // Nonzero requirement: SteamAppId=0 (the launcher itself) is ignored.
-        assert_eq!(parse_steam_app_id_from_environ(b"SteamAppId=0\0FOO=bar\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"SteamAppId=0\0FOO=bar\0"),
+            None
+        );
         // Absent → None (a non-Steam process).
-        assert_eq!(parse_steam_app_id_from_environ(b"PATH=/usr/bin\0HOME=/home/x\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"PATH=/usr/bin\0HOME=/home/x\0"),
+            None
+        );
         // Not fooled by a different var that merely contains the substring.
-        assert_eq!(parse_steam_app_id_from_environ(b"MY_SteamAppId=999\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"MY_SteamAppId=999\0"),
+            None
+        );
         // Garbage value → None, no panic.
-        assert_eq!(parse_steam_app_id_from_environ(b"SteamAppId=notanumber\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"SteamAppId=notanumber\0"),
+            None
+        );
     }
 
     #[test]