fix: prettier formatting, viteStaticCopy paths, HydrateFallback warning

- Fix prettier formatting in useCall.ts and initMatrix.ts (unblocks CI)
- Fix viteStaticCopy stripBase so manifest.json and public/locales/ land
  at correct output paths (was getting extra 'public/' prefix from v4 path
  preservation behavior)
- Silence react-router v7 HydrateFallback warning on root route (SPA has
  no SSR hydration, null is intentional)

src/app/pages/Router.tsx

@@ -104,7 +104,7 @@ export const createRouter = (clientConfig: ClientConfig, screenSize: ScreenSize)
   const mobile = screenSize === ScreenSize.Mobile;
 
   const routes = createRoutesFromElements(
-    <Route>
+    <Route hydrateFallbackElement={null}>
       <Route
         index
         loader={() => {