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/http-json/tests/http_json_tests.rs

@@ -1,19 +1,23 @@
-use std::time::Duration;
-use axum::{Router, routing::get, response::Json};
+use axum::{Router, response::Json, routing::get};
 use domain::{DataSource, DataSourceConfig, DataSourcePort, DataSourceType, Value};
 use http_json::HttpJsonAdapter;
+use std::time::Duration;
 
 async fn start_fake_api() -> String {
     let app = Router::new()
-        .route("/weather", get(|| async {
-            Json(serde_json::json!({
-                "main": {"temp": 5.4, "humidity": 80},
-                "weather": [{"icon": "cloud_rain"}]
-            }))
-        }))
-        .route("/simple", get(|| async {
-            Json(serde_json::json!({"value": "hello"}))
-        }))
+        .route(
+            "/weather",
+            get(|| async {
+                Json(serde_json::json!({
+                    "main": {"temp": 5.4, "humidity": 80},
+                    "weather": [{"icon": "cloud_rain"}]
+                }))
+            }),
+        )
+        .route(
+            "/simple",
+            get(|| async { Json(serde_json::json!({"value": "hello"})) }),
+        )
         .route("/not-json", get(|| async { "plain text" }));
 
     let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
@@ -46,10 +50,7 @@ async fn polls_url_and_returns_nested_json_as_value() {
 
     let result = adapter.poll(&source).await.unwrap();
 
-    assert_eq!(
-        result.get_path("$.main.temp"),
-        Some(&Value::Number(5.4))
-    );
+    assert_eq!(result.get_path("$.main.temp"), Some(&Value::Number(5.4)));
     assert_eq!(
         result.get_path("$.main.humidity"),
         Some(&Value::Number(80.0))