Shift freezeAnimation to URL as source of truth

docs/APP_REFACTORING_DESIGN.md

@@ -94,7 +94,7 @@ We will gradually eliminate React state variables in `src/app.tsx` and derive th
 *   [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.
 *   [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.
+*   [x] **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.
 *   [ ] **Step 3.4:** Extract `config` state. Parse display settings on render using `argsToConfig` helper. Remove state. In `ViewPage`, run `updateChartWithConfig(config, data)` synchronously during the render pass (e.g. in the `useMemo` that derives query parameters/config) to update the in-memory chart data before it is rendered by the `<Chart>` child component. Run E2E and visual tests to verify no rendering regressions occurred.

src/app.tsx

@@ -96,8 +96,7 @@ export function App() {
   const [showErrorPopup, setShowErrorPopup] = useState(false);
   /** Specification of the source of the data. */
   const [sourceSpec, setSourceSpec] = useState<DataSourceSpec>();
-  /** Freeze animations after initial chart render. */
-  const [freezeAnimation, setFreezeAnimation] = useState(false);
+
   /** Configuration settings for chart display options (e.g. colors, hiding IDs). */
   const [config, setConfig] = useState(DEFALUT_CONFIG);
 
@@ -124,6 +123,8 @@ export function App() {
    * from WikiTree.
    */
   const showWikiTreeMenus = args.showWikiTreeMenus;
+  /** Freeze animations after initial chart render. */
+  const freezeAnimation = args.freezeAnimation;
 
   /** Prevents the Google Drive "Open with" state from being processed more than once. */
   const stateProcessed = useRef(false);
@@ -354,7 +355,6 @@ export function App() {
         setSourceSpec(args.sourceSpec);
         setSelection(args.selection);
         setDetailIndi(args.selection?.id);
-        setFreezeAnimation(args.freezeAnimation);
         setConfig(args.config);
         const currentFetchId = ++fetchIdRef.current;
         setLoadingStatus('Loading…');