fix(desktop): preload must be .cjs, not .js (apps/desktop has type:module)

Previous fix wrote CJS code but kept .js extension. Because
apps/desktop/package.json has "type":"module", Node treated the
.js preload as ESM and refused to load it — silently — so window.codesign
never got exposed and every IPC call failed with 'Renderer not connected'.

Use .cjs extension so Node honors the format regardless of package type.

Signed-off-by: hqhq1025 <1506751656@qq.com>

Author: hqhq1025

apps/desktop/electron.vite.config.ts

@@ -17,7 +17,7 @@ export default defineConfig({
       outDir: 'out/preload',
       rollupOptions: {
         input: { index: resolve(__dirname, 'src/preload/index.ts') },
-        output: { format: 'cjs', entryFileNames: 'index.js' },
+        output: { format: 'cjs', entryFileNames: 'index.cjs' },
       },
     },
   },