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/scan.rs

@@ -62,7 +62,7 @@ fn linux_proc_executables() -> Vec<String> {
 fn windows_toolhelp_executables() -> Vec<String> {
     use windows_sys::Win32::Foundation::{CloseHandle, INVALID_HANDLE_VALUE};
     use windows_sys::Win32::System::Diagnostics::ToolHelp::{
-        CreateToolhelp32Snapshot, Process32FirstW, Process32NextW, PROCESSENTRY32W,
+        CreateToolhelp32Snapshot, PROCESSENTRY32W, Process32FirstW, Process32NextW,
         TH32CS_SNAPPROCESS,
     };
 
@@ -78,7 +78,11 @@ fn windows_toolhelp_executables() -> Vec<String> {
     let mut ok = unsafe { Process32FirstW(snapshot, &mut entry) };
     while ok != 0 {
         // szExeFile is a NUL-terminated UTF-16 array (the basename, e.g. game.exe).
-        let end = entry.szExeFile.iter().position(|&c| c == 0).unwrap_or(entry.szExeFile.len());
+        let end = entry
+            .szExeFile
+            .iter()
+            .position(|&c| c == 0)
+            .unwrap_or(entry.szExeFile.len());
         let name = String::from_utf16_lossy(&entry.szExeFile[..end]);
         if !name.is_empty() {
             out.push(name);
@@ -101,7 +105,10 @@ mod tests {
         // The test runner itself is a process, so /proc enumeration must be
         // non-empty and include something that normalizes to our own exe basename.
         let exes = running_executables();
-        assert!(!exes.is_empty(), "expected to see running processes via /proc");
+        assert!(
+            !exes.is_empty(),
+            "expected to see running processes via /proc"
+        );
         // Our own /proc/self/exe basename should appear among them.
         let me = std::fs::read_link("/proc/self/exe")
             .ok()
@@ -109,7 +116,8 @@ mod tests {
         if let Some(me) = me {
             let me_norm = super::super::normalize_exe(&me);
             assert!(
-                exes.iter().any(|e| super::super::normalize_exe(e) == me_norm),
+                exes.iter()
+                    .any(|e| super::super::normalize_exe(e) == me_norm),
                 "running list should include our own executable {me_norm:?}"
             );
         }