fix(pptx): externalize fflate in the browser entry

[Taozizz]

Root cause

tsup.config.ts listed fflate in noExternal while tsup's default platform is node, so esbuild resolved fflate's exports map through the node condition and inlined the Node ESM build (esm/index.mjs) into dist/browser.js. Its module-scope, unguarded

import { createRequire } from "module";
var require2 = createRequire("/");

breaks every downstream browser bundler ("createRequire" is not exported by "__vite-browser-external" on Vite/Rollup; webpack fails resolving module), and crashes the Vite dev server at module evaluation.

Fix

Option 3 from the issue, matching docx-core and xlsx-core which are unaffected for exactly this reason:

• drop fflate from noExternal;
• declare fflate: ^0.8.2 as a regular dependency.

dist/browser.js now keeps a bare import { Unzip, UnzipInflate } from "fflate", which consumer bundlers resolve through fflate's own exports map — browser builds get esm/browser.js. Zero occurrences of createRequire/worker_threads remain in the published dist.

Gate hardening

The release gates missed this because nothing ever bundled dist/browser.js:

• the external tgz consumer template now imports every package's secondary entries (@arcships/pptx-core/browser, @arcships/vue-pptx, @arcships/vue-xlsx/chart|map|webgl), so entry-level bundling regressions fail the gate's vite build;
• the template mounts PptxViewer beside the DOCX/XLSX/PDF viewers and wires its load state into the aggregate readiness check, so module-evaluation crashes fail the browser check too;
• verify-pptx-consumer.mjs now packs workspace @arcships/office-interaction and overrides it, instead of resolving the unpublished 0.6.0 from the registry (the standalone gate could not run at all since the 0.6.0 candidate bump).

Verification

• pnpm test:pptx: 21/21 tests pass; verify-pptx-consumer passes end to end (tgz → out-of-workspace install → tsc + vite build → preview → Playwright click-animation check).
• pnpm test:consumer: 9 tgz contract checks + hardened external consumer gate (npm install, tsc, vue-tsc, vite build, Playwright blackbox) all pass.
• Downstream repro: a real Vite 5 + vue-tsc app consuming the packed tgzs builds clean with its module-alias workaround removed; the pptx vendor chunk contains no Node remnants.

Fixes #1