chore: upgrade i18next 26, prettier 3, fontsource-variable, domhandler 6, lint-staged 17

- i18next 23->26 + react-i18next 15->17
- prettier 2->3, reformat all files
- replace @fontsource/inter with @fontsource-variable/inter 5, update import path
- domhandler 5->6 (aligns with transitive deps)
- lint-staged 16->17

src/app/hooks/useMatrixEventRenderer.ts

@@ -14,7 +14,7 @@ export const useMatrixEventRenderer =
   <T extends unknown[]>(
     typeToRenderer: EventRendererOpts<T>,
     renderStateEvent?: EventRenderer<T>,
-    renderEvent?: EventRenderer<T>
+    renderEvent?: EventRenderer<T>,
   ): RenderMatrixEvent<T> =>
   (eventType, isStateEvent, ...args) => {
     const renderer = typeToRenderer[eventType];