Shift showWikiTreeMenus to URL as source of truth

docs/APP_REFACTORING_DESIGN.md

@@ -93,7 +93,7 @@ To refactor `app.tsx` safely and maintain continuous code correctness, we will m
 We will gradually eliminate React state variables in `src/app.tsx` and derive them (including settings like `standalone`, `showWikiTreeMenus`, and `freezeAnimation`) directly from the `useLocation()` search query parameters on render:
 *   [x] **Step 3.1a:** Shift `chartType` to URL as SSOT. Derive it using `useMemo` from search parameters, replace calls to `setChartType` with URL updates, and remove the React state variable and sync effect.
 *   [x] **Step 3.1b:** Shift `standalone` to URL as SSOT. Derive it directly from search parameters on render and remove its React state variable.
-*   [ ] **Step 3.1c:** Shift `showWikiTreeMenus` to URL as SSOT. Derive it directly from search parameters on render and remove its React state variable.
+*   [x] **Step 3.1c:** Shift `showWikiTreeMenus` to URL as SSOT. Derive it directly from search parameters on render and remove its React state variable.
 *   [ ] **Step 3.1d:** Shift `freezeAnimation` to URL as SSOT. Derive it directly from search parameters on render and remove its React state variable.
 *   [ ] **Step 3.2:** Extract `selection` and `detailIndi` state. Parse them directly from URL params (`indi`, `gen`, and `detail`); update display selectors. Remove React states. Ensure that chart selection changes (`onSelection` callback) explicitly clear or update the `detail` query parameter to match the new selection to avoid getting stuck on the old details viewport. Also update the detail-only selection handler (`onDetailSelection`) to update the `detail` query parameter in the URL.
 *   [ ] **Step 3.3:** Extract `showSidePanel` state. Derive state directly from `?sidePanel=` parameter. Remove React state. Enhance URL args helpers to allow generating path/query target objects with replaced values, and ensure layout settings (`sidePanel`) and configuration changes use `replace: true` to prevent polluting the browser history stack.

src/app.tsx

@@ -92,12 +92,6 @@ export function App() {
   /** Whether the side panel is shown. */
   const [showSidePanel, setShowSidePanel] = useState(false);
 
-  /**
-   * Whether the app should display WikiTree-specific menus when showing data
-   * from WikiTree.
-   */
-  const [showWikiTreeMenus, setShowWikiTreeMenus] = useState(true);
-
   /** Whether to show the error popup. */
   const [showErrorPopup, setShowErrorPopup] = useState(false);
   /** Specification of the source of the data. */
@@ -125,6 +119,11 @@ export function App() {
   const chartType = args.chartType;
   /** Whether the app is in standalone mode, i.e. showing 'open file' menus. */
   const standalone = args.standalone;
+  /**
+   * Whether the app should display WikiTree-specific menus when showing data
+   * from WikiTree.
+   */
+  const showWikiTreeMenus = args.showWikiTreeMenus;
 
   /** Prevents the Google Drive "Open with" state from being processed more than once. */
   const stateProcessed = useRef(false);
@@ -355,7 +354,6 @@ export function App() {
         setSourceSpec(args.sourceSpec);
         setSelection(args.selection);
         setDetailIndi(args.selection?.id);
-        setShowWikiTreeMenus(args.showWikiTreeMenus);
         setFreezeAnimation(args.freezeAnimation);
         setConfig(args.config);
         const currentFetchId = ++fetchIdRef.current;