fix: match context panel backgrounds to sidebar

Change JiraView, TodosView, and ProblemsView backgrounds from
\$background to \$surface so the right panel visually matches the
left sidebar panel.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clide/widgets/components/jira_view.py

@@ -12,7 +12,7 @@ class JiraView(Vertical):
     DEFAULT_CSS = """
     JiraView {
         height: 1fr;
-        background: $background;
+        background: $surface;
     }
 
     JiraView .jira-header {

clide/widgets/components/problems_view.py

@@ -42,7 +42,7 @@ class ProblemsView(TileListView):
     DEFAULT_CSS = """
     ProblemsView {
         height: 1fr;
-        background: $background;
+        background: $surface;
     }
 
     ProblemsView .problems-header {

clide/widgets/components/todos_view.py

@@ -97,7 +97,7 @@ class TodosView(TileListView):
     DEFAULT_CSS = """
     TodosView {
         height: 1fr;
-        background: $background;
+        background: $surface;
     }
 
     TodosView TabbedContent {