add SPA config UI, wire media/rss adapters, event-driven layout push

- React SPA: dashboard, data sources CRUD, widgets CRUD, layout builder,
  presets. TanStack Router + Query, shadcn/ui, Vite proxy to :3000
- wire media + rss adapters into polling loop, remove xtb source type
- media adapter: read username/password from headers, proper subsonic auth
- event handler: subscribe to LayoutChanged, push screen update to clients
- fix clippy warnings across workspace (Default impls, collapsible ifs,
  redundant closures, is_none_or, unused imports)

crates/adapters/config-memory/src/lib.rs

@@ -1,10 +1,9 @@
+use domain::{
+    ConfigRepository, DataSource, DataSourceId, Layout, LayoutPreset, LayoutPresetId, WidgetConfig,
+    WidgetId,
+};
 use std::collections::HashMap;
 use std::sync::RwLock;
-use domain::{
-    ConfigRepository,
-    DataSource, DataSourceId, Layout, LayoutPreset, LayoutPresetId,
-    WidgetConfig, WidgetId,
-};
 
 #[derive(Debug, thiserror::Error)]
 pub enum MemoryConfigError {
@@ -19,8 +18,8 @@ pub struct MemoryConfigStore {
     presets: RwLock<HashMap<LayoutPresetId, LayoutPreset>>,
 }
 
-impl MemoryConfigStore {
-    pub fn new() -> Self {
+impl Default for MemoryConfigStore {
+    fn default() -> Self {
         Self {
             widgets: RwLock::new(HashMap::new()),
             data_sources: RwLock::new(HashMap::new()),
@@ -30,82 +29,130 @@ impl MemoryConfigStore {
     }
 }
 
+impl MemoryConfigStore {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
 impl ConfigRepository for MemoryConfigStore {
     type Error = MemoryConfigError;
 
     async fn get_widget(&self, id: WidgetId) -> Result<Option<WidgetConfig>, Self::Error> {
-        let guard = self.widgets.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .widgets
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.get(&id).cloned())
     }
 
     async fn list_widgets(&self) -> Result<Vec<WidgetConfig>, Self::Error> {
-        let guard = self.widgets.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .widgets
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.values().cloned().collect())
     }
 
     async fn save_widget(&self, config: &WidgetConfig) -> Result<(), Self::Error> {
-        let mut guard = self.widgets.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .widgets
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.insert(config.id, config.clone());
         Ok(())
     }
 
     async fn delete_widget(&self, id: WidgetId) -> Result<(), Self::Error> {
-        let mut guard = self.widgets.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .widgets
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.remove(&id);
         Ok(())
     }
 
     async fn get_data_source(&self, id: DataSourceId) -> Result<Option<DataSource>, Self::Error> {
-        let guard = self.data_sources.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .data_sources
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.get(&id).cloned())
     }
 
     async fn list_data_sources(&self) -> Result<Vec<DataSource>, Self::Error> {
-        let guard = self.data_sources.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .data_sources
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.values().cloned().collect())
     }
 
     async fn save_data_source(&self, source: &DataSource) -> Result<(), Self::Error> {
-        let mut guard = self.data_sources.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .data_sources
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.insert(source.id, source.clone());
         Ok(())
     }
 
     async fn delete_data_source(&self, id: DataSourceId) -> Result<(), Self::Error> {
-        let mut guard = self.data_sources.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .data_sources
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.remove(&id);
         Ok(())
     }
 
     async fn get_layout(&self) -> Result<Option<Layout>, Self::Error> {
-        let guard = self.layout.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .layout
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.clone())
     }
 
     async fn save_layout(&self, layout: &Layout) -> Result<(), Self::Error> {
-        let mut guard = self.layout.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .layout
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         *guard = Some(layout.clone());
         Ok(())
     }
 
     async fn get_preset(&self, id: LayoutPresetId) -> Result<Option<LayoutPreset>, Self::Error> {
-        let guard = self.presets.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .presets
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.get(&id).cloned())
     }
 
     async fn list_presets(&self) -> Result<Vec<LayoutPreset>, Self::Error> {
-        let guard = self.presets.read().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let guard = self
+            .presets
+            .read()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         Ok(guard.values().cloned().collect())
     }
 
     async fn save_preset(&self, preset: &LayoutPreset) -> Result<(), Self::Error> {
-        let mut guard = self.presets.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .presets
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.insert(preset.id, preset.clone());
         Ok(())
     }
 
     async fn delete_preset(&self, id: LayoutPresetId) -> Result<(), Self::Error> {
-        let mut guard = self.presets.write().map_err(|_| MemoryConfigError::LockPoisoned)?;
+        let mut guard = self
+            .presets
+            .write()
+            .map_err(|_| MemoryConfigError::LockPoisoned)?;
         guard.remove(&id);
         Ok(())
     }