fix(core): add null checks for timeout refs and event listeners for React 19 compatibility (#9116)

## Description
- Add null checks before clearTimeout calls in colorful-fallback.tsx, edgeless.dialog.tsx, and local.dialog.tsx
- Fix event listener cleanup in unfolding.tsx
- Update tsconfig.jsx to use react-jsx transform

## Testing
- [x] Verified type safety improvements for React 19 compatibility
- [x] Ensured proper cleanup of event listeners and timeouts
- [x] Confirmed no unintended side effects from the changes

Link to Devin run: https://app.devin.ai/sessions/2e790f3ea0d84402837ec6c3c6f83e4c

packages/frontend/core/src/modules/app-sidebar/views/menu-item/external-menu-link-item.tsx

@@ -1,6 +1,6 @@
 import { DualLinkIcon } from '@blocksuite/icons/rc';
 import { cssVarV2 } from '@toeverything/theme/v2';
-import type { ReactElement } from 'react';
+import type { ReactElement, SVGAttributes } from 'react';
 import type { To } from 'react-router-dom';
 
 import { MenuLinkItem } from './index';
@@ -28,7 +28,7 @@ export const ExternalMenuLinkItem = ({
   label,
 }: {
   href: string;
-  icon: ReactElement;
+  icon: ReactElement<SVGAttributes<SVGElement>>;
   label: string;
 }) => {
   return (

packages/frontend/core/src/modules/app-sidebar/views/menu-item/index.tsx

@@ -1,13 +1,13 @@
 import { WorkbenchLink } from '@affine/core/modules/workbench';
 import { ArrowDownSmallIcon } from '@blocksuite/icons/rc';
 import clsx from 'clsx';
-import React from 'react';
+import React, { type SVGAttributes } from 'react';
 import type { To } from 'react-router-dom';
 
 import * as styles from './index.css';
 
 export interface MenuItemProps extends React.HTMLAttributes<HTMLDivElement> {
-  icon?: React.ReactElement;
+  icon?: React.ReactElement<SVGAttributes<SVGElement>>;
   active?: boolean;
   disabled?: boolean;
   // true, false, undefined. undefined means no collapse