fix: add type annotation to VITE_PLUS_VERSION for isolatedDeclarations

rolldown-vite uses --isolatedDeclarations which requires explicit type
annotations. Add `: string` to the VITE_PLUS_VERSION constant.

Author: fengmk2

packages/tools/src/brand-rolldown-vite.ts

@@ -72,7 +72,7 @@ export function brandRolldownVite(rootDir: string = process.cwd()) {
     replaceInFile(
       constantsFile,
       'export const VERSION = version as string',
-      'export const VERSION = version as string\n\nexport const VITE_PLUS_VERSION = process.env.VITE_PLUS_VERSION || VERSION',
+      'export const VERSION = version as string\n\nexport const VITE_PLUS_VERSION: string = process.env.VITE_PLUS_VERSION || VERSION',
     ),
   );