new file: Makefile

new file:   TODO.md
	modified:   src/config.rs
	modified:   src/detect.rs
	modified:   src/diagnose.rs
	new file:   src/gui.rs
	modified:   src/main.rs
	modified:   src/service.rs
	modified:   src/setup.rs
	modified:   src/tray.rs
	new file:   src/util.rs
	new file:   umutray.desktop

src/detect.rs

@@ -3,6 +3,38 @@ use anyhow::Result;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 
+#[derive(Debug, Clone)]
+pub struct DetectHit {
+    pub display: String,
+    pub prefix: PathBuf,
+    /// True if this launcher is already in config with this exact prefix.
+    pub configured: bool,
+}
+
+/// Scan default Wine prefix locations and return hits against known presets.
+pub fn scan_for_gui(config: &Config) -> Vec<DetectHit> {
+    let roots: Vec<PathBuf> = default_roots().into_iter().filter(|r| r.is_dir()).collect();
+    let prefixes = scan_prefixes(&roots);
+    let mut hits = Vec::new();
+    for preset in crate::config::presets() {
+        for prefix in &prefixes {
+            if prefix.join("drive_c").join(&preset.exe_path).exists() {
+                let configured = config
+                    .find(&preset.name)
+                    .map(|l| l.prefix_dir == *prefix)
+                    .unwrap_or(false);
+                hits.push(DetectHit {
+                    display: preset.display.clone(),
+                    prefix: prefix.clone(),
+                    configured,
+                });
+                break;
+            }
+        }
+    }
+    hits
+}
+
 const MAX_DEPTH: u32 = 3;
 
 pub fn run(config: &Config, extra_dirs: &[PathBuf], apply: bool) -> Result<()> {