Remove umu-run, keep game as child process for Steam tracking

- Remove umu-run entirely (crashed due to pressure-vessel/FUSE
  incompatibility) — use raw `proton run` instead
- Replace startDetached() with QProcess::start() so the game stays in
  Fluorine's process tree. This lets Steam track the game lifetime and
  makes the "close game" button work when Fluorine is added as a
  non-Steam game.
- Add writeIniValueDirect/readIniValueDirect for safe Bethesda INI
  handling without QSettings corruption
- Fix prefix_setup.rs to skip umu-run bootstrapping
- Clean up settings UI, build scripts, and docs for umu-run removal

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 3 insertions, 17 deletions

diff --git a/libs/nak/src/installers/prefix_setup.rs b/libs/nak/src/installers/prefix_setup.rs
index 4f27606..468aaa2 100644
--- a/libs/nak/src/installers/prefix_setup.rs
+++ b/libs/nak/src/installers/prefix_setup.rs
@@ -297,23 +297,9 @@ fn initialize_prefix_with_proton(
         ("WINEDLLOVERRIDES", "msdia80.dll=n;conhost.exe=d;cmd.exe=d".to_string()),
     ];
 
-    let (exe, args): (std::path::PathBuf, Vec<&str>) = if runtime_wrap::use_umu_for_prefix() {
-        if let Some(umu_run) = runtime_wrap::resolve_umu_run() {
-            log_install(&format!("Initializing prefix with umu-run: {:?}", umu_run));
-            envs.push(("PROTONPATH", proton.path.display().to_string()));
-            envs.push(("WINEPREFIX", prefix_root.display().to_string()));
-            envs.push(("GAMEID", app_id.to_string()));
-            (umu_run, vec!["wineboot", "-u"])
-        } else {
-            log_warning(
-                "UMU prefix mode enabled but no umu-run was found; falling back to proton wrapper",
-            );
-            (proton_script.clone(), vec!["run", "wineboot", "-u"])
-        }
-    } else {
-        log_install(&format!("Initializing prefix with proton wrapper: {:?}", proton_script));
-        (proton_script.clone(), vec!["run", "wineboot", "-u"])
-    };
+    log_install(&format!("Initializing prefix with proton wrapper: {:?}", proton_script));
+    let (exe, args): (std::path::PathBuf, Vec<&str>) =
+        (proton_script.clone(), vec!["run", "wineboot", "-u"]);
 
     let mut cmd = runtime_wrap::build_command(&exe, &envs);
     cmd.args(&args);