Async downloader, better Proton support (#183)

* feat: async downloader + other fixes

* feat: windows command parsing + use library path for install path

* feat: better proton support

* feat: style fixes and store button now uses in-app

* feat: emulator rename + umu emulator fix

* feat: bring process creation inline with docs

* fix: clippy

desktop/src-tauri/process/src/error.rs

@@ -1,4 +1,8 @@
-use std::{fmt::Display, io::{self, Error}, sync::Arc};
+use std::{
+    fmt::Display,
+    io::{self, Error},
+    sync::Arc,
+};
 
 use serde_with::SerializeDisplay;
 
@@ -15,6 +19,7 @@ pub enum ProcessError {
     OpenerError(Arc<tauri_plugin_opener::Error>),
     InvalidArguments(String),
     FailedLaunch(String),
+    NoCompat,
 }
 
 impl Display for ProcessError {
@@ -38,6 +43,7 @@ impl Display for ProcessError {
                 "Missing a required dependency to launch this game: {} {}",
                 game_id, version_id
             ),
+            ProcessError::NoCompat => "No Proton compatibility layer could be found for this tool. Add an override or set your global default in settings.",
         };
         write!(f, "{s}")
     }
@@ -47,4 +53,4 @@ impl From<io::Error> for ProcessError {
     fn from(value: io::Error) -> Self {
         ProcessError::IOError(Arc::new(value))
     }
-}
+}