Raise the chunk size warning limit to 5 MB

The 500 kB default is meant for websites, but Tauri loads the bundle
from disk. The limit stays close to the main chunk's size, so we still
hear about it when it grows noticeably.

vite.config.ts

@@ -69,6 +69,7 @@ export default defineConfig({
   ],
   build: {
     outDir: "build",
+    chunkSizeWarningLimit: 5000,
   },
   // prevent vite from obscuring rust errors
   clearScreen: false,