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/client-domain/tests/layout_engine_tests.rs

@@ -1,7 +1,5 @@
-use domain::{
-    LayoutNode, ContainerNode, LayoutChild, Direction, Sizing,
-};
 use client_domain::{BoundingBox, LayoutEngine, RenderTree};
+use domain::{ContainerNode, Direction, LayoutChild, LayoutNode, Sizing};
 
 fn screen() -> BoundingBox {
     BoundingBox::screen(240, 320)
@@ -73,9 +71,18 @@ fn row_splits_width_among_equal_flex_children() {
     let layout = row(vec![leaf(1), leaf(2), leaf(3)]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 80, 320)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(80, 0, 80, 320)));
-    assert_eq!(tree.get_widget_bounds(3), Some(&BoundingBox::new(160, 0, 80, 320)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 80, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(80, 0, 80, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(3),
+        Some(&BoundingBox::new(160, 0, 80, 320))
+    );
 }
 
 #[test]
@@ -83,8 +90,14 @@ fn column_splits_height_among_equal_flex_children() {
     let layout = column(vec![leaf(1), leaf(2)]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 240, 160)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(0, 160, 240, 160)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 240, 160))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(0, 160, 240, 160))
+    );
 }
 
 #[test]
@@ -92,8 +105,14 @@ fn fixed_and_flex_children_coexist() {
     let layout = row(vec![leaf_fixed(1, 40), leaf(2)]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 40, 320)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(40, 0, 200, 320)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 40, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(40, 0, 200, 320))
+    );
 }
 
 #[test]
@@ -102,8 +121,14 @@ fn gap_is_subtracted_before_distributing_space() {
     let layout = row_with_gap(10, vec![leaf(1), leaf(2)]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 115, 320)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(125, 0, 115, 320)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 115, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(125, 0, 115, 320))
+    );
 }
 
 #[test]
@@ -112,7 +137,10 @@ fn padding_insets_available_area() {
     let layout = row_with_padding(10, vec![leaf(1)]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(10, 10, 220, 300)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(10, 10, 220, 300))
+    );
 }
 
 #[test]
@@ -125,9 +153,18 @@ fn nested_containers_compute_correctly() {
     let layout = row(vec![leaf(1), inner_col]);
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 120, 320)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(120, 0, 120, 160)));
-    assert_eq!(tree.get_widget_bounds(3), Some(&BoundingBox::new(120, 160, 120, 160)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 120, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(120, 0, 120, 160))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(3),
+        Some(&BoundingBox::new(120, 160, 120, 160))
+    );
 }
 
 #[test]
@@ -138,14 +175,32 @@ fn weighted_flex_distributes_proportionally() {
         gap: 0,
         padding: 0,
         children: vec![
-            LayoutChild { sizing: Sizing::Flex(1), node: LayoutNode::Leaf(1) },
-            LayoutChild { sizing: Sizing::Flex(2), node: LayoutNode::Leaf(2) },
-            LayoutChild { sizing: Sizing::Flex(1), node: LayoutNode::Leaf(3) },
+            LayoutChild {
+                sizing: Sizing::Flex(1),
+                node: LayoutNode::Leaf(1),
+            },
+            LayoutChild {
+                sizing: Sizing::Flex(2),
+                node: LayoutNode::Leaf(2),
+            },
+            LayoutChild {
+                sizing: Sizing::Flex(1),
+                node: LayoutNode::Leaf(3),
+            },
         ],
     });
     let tree = LayoutEngine::compute(&layout, screen());
 
-    assert_eq!(tree.get_widget_bounds(1), Some(&BoundingBox::new(0, 0, 60, 320)));
-    assert_eq!(tree.get_widget_bounds(2), Some(&BoundingBox::new(60, 0, 120, 320)));
-    assert_eq!(tree.get_widget_bounds(3), Some(&BoundingBox::new(180, 0, 60, 320)));
+    assert_eq!(
+        tree.get_widget_bounds(1),
+        Some(&BoundingBox::new(0, 0, 60, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(2),
+        Some(&BoundingBox::new(60, 0, 120, 320))
+    );
+    assert_eq!(
+        tree.get_widget_bounds(3),
+        Some(&BoundingBox::new(180, 0, 60, 320))
+    );
 }