feat: implement backlog plan management and UI enhancements

- Added functionality to save, clear, and load backlog plans within the application.
- Introduced a new API endpoint for clearing saved backlog plans.
- Enhanced the backlog plan dialog to allow users to review and apply changes to their features.
- Integrated dependency management features in the UI, allowing users to select parent and child dependencies for features.
- Improved the graph view with options to manage plans and visualize dependencies effectively.
- Updated the sidebar and settings to include provider visibility toggles for better user control over model selection.

These changes aim to enhance the user experience by providing robust backlog management capabilities and improving the overall UI for feature planning.

libs/types/src/settings.ts

@@ -418,6 +418,10 @@ export interface GlobalSettings {
   /** Which dynamic OpenCode models are enabled (empty = all discovered) */
   enabledDynamicModelIds?: string[];
 
+  // Provider Visibility Settings
+  /** Providers that are disabled and should not appear in model dropdowns */
+  disabledProviders?: ModelProvider[];
+
   // Input Configuration
   /** User's keyboard shortcut bindings */
   keyboardShortcuts: KeyboardShortcuts;
@@ -730,6 +734,7 @@ export const DEFAULT_GLOBAL_SETTINGS: GlobalSettings = {
   enabledOpencodeModels: getAllOpencodeModelIds(),
   opencodeDefaultModel: DEFAULT_OPENCODE_MODEL,
   enabledDynamicModelIds: [],
+  disabledProviders: [],
   keyboardShortcuts: DEFAULT_KEYBOARD_SHORTCUTS,
   projects: [],
   trashedProjects: [],