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/features/common-settings/developer-tools/SendRoomEvent.tsx

@@ -40,7 +40,7 @@ export function SendRoomEvent({ type, stateKey, requestClose }: SendRoomEventPro
   const [jsonError, setJSONError] = useState<SyntaxError>();
   const { handleKeyDown, operations, getTarget } = useTextAreaCodeEditor(
     textAreaRef,
-    EDITOR_INTENT_SPACE_COUNT
+    EDITOR_INTENT_SPACE_COUNT,
   );
 
   const [submitState, submit] = useAsyncCallback<
@@ -55,8 +55,8 @@ export function SendRoomEvent({ type, stateKey, requestClose }: SendRoomEventPro
         }
         return mx.sendEvent(room.roomId, evtType as any, evtContent);
       },
-      [mx, room]
-    )
+      [mx, room],
+    ),
   );
   const submitting = submitState.status === AsyncStatus.Loading;