To exclude all JSON files except manifest.json from the zip, you can configure the zip.exclude option in your wxt.config.ts file as follows:

// wxt.config.ts
import { defineConfig } from 'wxt';

export default defineConfig({
  zip: {
    exclude: [
      '**/*.json',       // Exclude all .json files
      '!manifest.json',  // Include manifest.json
    ],
  },
});

Here's how this configuration works:

    '**/*.json' excludes all files with the .json extension in any directory.
    '!manifest.json' is a negative pattern that includes manifest.json, overriding the previous exclusion.

Make sure that the paths specified in the exclude array are relative to the root of the WXT project.