fix(schema): parse node-status banner and layout UI sections

The UI-schema loader walked a hardcoded list of flat TOML sections and
left [banners.*] and [layout] out, so those sections in ui.toml were
silently dropped. The node-status error strip at the top of the content
column could not be styled from the schema at all.

- The flat-section list is now one shared constant used by the file,
  string and overlay loaders, and it includes banners and layout.
- The node-status banner is themeable from ui.toml like every other
  section; a note in the toml records that these parse as flat sections.

No visible change unless ui.toml overrides those sections.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

res/themes/ui.toml

@@ -700,6 +700,7 @@ status-pill-bg-alpha = { size = 30 }
 status-pill-y-offset = { size = 1 }
 confirmed-threshold = { size = 10 }
 
+# NOTE: [banners.*] and [layout] are parsed as flat sections (kFlatSections in ui_schema.cpp).
 # Persistent node/RPC error strip at the top of the content column (see App::renderNodeStatusBanner).
 # Slightly taller than the per-tab sync banner so it comfortably holds the Reconnect/Restart action.
 [banners.node-status]

src/ui/schema/ui_schema.cpp

@@ -21,6 +21,16 @@ namespace dragonx {
 namespace ui {
 namespace schema {
 
+namespace {
+// 2-level sections (sectionName.elementName -> {style object}) shared by all loaders.
+const char* const kFlatSections[] = {"business", "animations", "console",
+    "backdrop", "shutdown", "notifications", "status-bar",
+    "qr-code", "content-area", "style", "responsive",
+    "spacing", "spacing-tokens", "button", "dialog", "input", "fonts",
+    "inline-dialogs", "sidebar", "panels", "typography",
+    "effects", "security", "banners", "layout"};
+} // namespace
+
 // ============================================================================
 // Singleton
 // ============================================================================
@@ -81,12 +91,7 @@ bool UISchema::loadFromFile(const std::string& path) {
     }
 
     // Parse flat sections (2-level: sectionName.elementName → {style object})
-    for (const auto& flatSection : {"business", "animations", "console",
+    for (const char* flatSection : kFlatSections) {
-            "backdrop", "shutdown", "notifications", "status-bar",
-            "qr-code", "content-area", "style", "responsive",
-            "spacing", "spacing-tokens", "button", "dialog", "input", "fonts",
-            "inline-dialogs", "sidebar", "panels", "typography",
-            "effects", "security"}) {
         if (auto* sec = root[flatSection].as_table()) {
             parseFlatSection(static_cast<const void*>(sec), flatSection);
         }
@@ -170,12 +175,7 @@ bool UISchema::loadFromString(const std::string& tomlStr, const std::string& lab
     }
 
     // Parse flat sections (2-level: sectionName.elementName → {style object})
-    for (const auto& flatSection : {"business", "animations", "console",
+    for (const char* flatSection : kFlatSections) {
-            "backdrop", "shutdown", "notifications", "status-bar",
-            "qr-code", "content-area", "style", "responsive",
-            "spacing", "spacing-tokens", "button", "dialog", "input", "fonts",
-            "inline-dialogs", "sidebar", "panels", "typography",
-            "effects", "security"}) {
         if (auto* sec = root[flatSection].as_table()) {
             parseFlatSection(static_cast<const void*>(sec), flatSection);
         }
@@ -250,12 +250,7 @@ bool UISchema::mergeOverlayFromFile(const std::string& path) {
     }
 
     // Merge all flat sections (2-level)
-    for (const auto& flatSection : {"business", "animations", "console",
+    for (const char* flatSection : kFlatSections) {
-            "backdrop", "shutdown", "notifications", "status-bar",
-            "qr-code", "content-area", "style", "responsive",
-            "spacing", "spacing-tokens", "button", "dialog", "input", "fonts",
-            "inline-dialogs", "sidebar", "panels", "typography",
-            "effects", "security"}) {
         if (auto* sec = root[flatSection].as_table()) {
             parseFlatSection(static_cast<const void*>(sec), flatSection);
         }