Pass config from main to the relevant places

src/backend/brightness_control.rs

@@ -143,12 +143,9 @@ impl BackendThread<BrightnessMessage, Sender<BrightnessMessage>> for BrightnessM
         &self.subscribers
     }
 
-    fn init(registration_rx: Receiver<Sender<BrightnessMessage>>) {
+    fn init(self, registration_rx: Receiver<Sender<BrightnessMessage>>) {
         let (f2b_tx, f2b_rx) = crossbeam_channel::unbounded::<BrightnessMessage>();
-        let instance = Arc::new(Mutex::new(Self {
-            display_cache: HashMap::new(),
-            subscribers: Vec::new(),
-        }));
+        let instance = Arc::new(Mutex::new(self));
         let instance_clone = instance.clone();
         thread::spawn(move || {
             while let Ok(tx) = registration_rx.recv() {
@@ -246,6 +243,12 @@ enum Operation {
 }
 
 impl BrightnessManager {
+    pub fn new() -> Self {
+        Self {
+            subscribers: vec![],
+            display_cache: HashMap::new(),
+        }
+    }
     pub fn set_brightness(&mut self, connector: String, percent: u8) {
         if !self.display_cache.contains_key(&connector) {
             self.register_display(connector.clone());