Fix browser WASM loader for remapped bundler builds

[lodyai]

Summary

• Fix the browser WASM loader used by bundler browser remaps so synchronous document XHR no longer sets responseType.
• Generate named WASM imports/re-exports for the browser patch so Parcel scope-hoisted builds can execute.
• Add explicit WASM re-exports in ESM package entrypoints and add a changeset.

Fixes #988

Validation

• pnpm dlx deno run -A ./scripts/build.ts release browser
• pnpm exec rollup -c
• PATH="$PWD/node_modules/.bin:$PATH" pnpm dlx deno run -A ./scripts/post-rollup.ts
• pnpm --dir examples/bundler-smoke-tests run test:fast
• pnpm --dir examples/bundler-smoke-tests run test:next
• Browser runtime matrix in Chromium/Playwright: Vite 5/6/7/8, Rolldown Vite, Webpack 5, Rsbuild 2, Rspack 2, Esbuild default/base64, Rollup default/base64, Parcel 2, Next 16 Turbopack, Next 16 Webpack.
• Issue repro repo /tmp/loro-issue-988: Vite dev page loads, dynamic new LoroDoc() succeeds, no page errors or console errors.
• pnpm dlx prettier --check crates/loro-wasm/scripts/browser_patch.js crates/loro-wasm/scripts/build.ts crates/loro-wasm/scripts/post-rollup.ts .changeset/fix-browser-sync-wasm.md
• git diff --check

[lodyai]

Additional validation completed for the exact browser snippet:

import { LoroDoc } from "loro-crdt"

const doc = new LoroDoc();
doc.getText("t").insert(0, "hi")
console.log(doc.toJSON()) // { t: "hi" }

I rebuilt the bundler smoke matrix with this snippet and verified in Chromium/Playwright that every case produced doc.toJSON() exactly equal to { t: "hi" }:

• Vite 5/6/7/8
• Rolldown Vite
• Webpack 5
• Rsbuild 2
• Rspack 2
• Esbuild default-copy/base64
• Rollup default-copy/base64
• Parcel 2
• Next 16 Turbopack
• Next 16 Webpack

All cases passed with no browser page errors or console errors.

[github-actions]

WASM Size Report

• Original size: 2999.99 KB
• Gzipped size: 990.47 KB
• Brotli size: 695.95 KB