feat: add Cloudflare Workers deployment alongside Vercel

InfiPlot now deploys to either Vercel or Cloudflare Workers — both
targets are first-class. The project is fully stateless (sessions live
on the client), so the Cloudflare side needs only Workers + Workers
Assets and zero D1/KV/R2.

- apps/web/wrangler.jsonc — nodejs_compat, Assets binding, 60s CPU
  limit (Workers Paid required; matches vercel.json maxDuration). I/O
  wait does not count against this budget — fits the LLM-bound
  workload that's most of the runtime.
- apps/web/open-next.config.ts — minimal defineCloudflareConfig (no
  cache needed since the engine is stateless).
- apps/web/package.json — added build:cf / preview:cf / deploy:cf via
  @opennextjs/cloudflare + wrangler (both devDeps); sharp moved from
  dependencies to devDependencies (only used by the manual
  optimize-home-images.mjs / localize-firstact-images.mjs scripts now).
- .gitignore — .open-next, .wrangler, .dev.vars.
- READMEs (3 langs) — Deploy to Cloudflare button next to Vercel,
  plus a Cloudflare section in the env-var setup (wrangler secret put
  + Cloudflare Access for staging access control).

Verified: pnpm typecheck + pnpm build (Vercel path) + pnpm build:cf
(OpenNext bundle: worker 4 KB, server 24 MB, assets 32 MB / 186
files — all within Workers limits) + pnpm preview:cf with the full
play loop (start → scene → background click → CORS-clean Canvas
annotation via Runware CDN → vision LLM → insert-beat) all green.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -39,9 +39,11 @@ InfiPlot是一款AI实时生成内容的互动剧情游戏，这里没有预设
 
 ## 一键部署
 
-[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https://github.com/zonghaoyuan/infiplot&root-directory=apps/web&env=TEXT_BASE_URL,TEXT_API_KEY,TEXT_MODEL,IMAGE_BASE_URL,IMAGE_API_KEY,IMAGE_MODEL,VISION_BASE_URL,VISION_API_KEY,VISION_MODEL,TTS_BASE_URL,TTS_API_KEY,TTS_SPEECH_MODEL,MOCK_IMAGE&envDescription=Three%20required%20providers%20%2B%20optional%20TTS.%20Any%20OpenAI-compatible%20endpoint%20works%20for%20text%2Fvision.%20TTS%20uses%20MiMo%27s%20own%20protocol.&envLink=https://github.com/zonghaoyuan/infiplot%23%E9%85%8D%E7%BD%AE%E6%95%99%E7%A8%8B)
+InfiPlot 同时支持部署到 Vercel 与 Cloudflare Workers —— 任选其一即可。
 
-部署完成后，在 Vercel 项目里填好环境变量 —— 详见下方的[配置教程](#配置教程)。Vercel 项目的 **Root Directory** 必须设为 `apps/web`（一键部署按钮会自动带上；若手动配置，请在 Project Settings 里设置）。
+[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https://github.com/zonghaoyuan/infiplot&root-directory=apps/web&env=TEXT_BASE_URL,TEXT_API_KEY,TEXT_MODEL,IMAGE_BASE_URL,IMAGE_API_KEY,IMAGE_MODEL,VISION_BASE_URL,VISION_API_KEY,VISION_MODEL,TTS_BASE_URL,TTS_API_KEY,TTS_SPEECH_MODEL,MOCK_IMAGE&envDescription=Three%20required%20providers%20%2B%20optional%20TTS.%20Any%20OpenAI-compatible%20endpoint%20works%20for%20text%2Fvision.%20TTS%20uses%20MiMo%27s%20own%20protocol.&envLink=https://github.com/zonghaoyuan/infiplot%23%E9%85%8D%E7%BD%AE%E6%95%99%E7%A8%8B)   [![Deploy to Cloudflare](https://deploy.workers.cloudflare.com/button)](https://deploy.workers.cloudflare.com/?url=https://github.com/zonghaoyuan/infiplot/tree/main/apps/web)
+
+部署完成后，填好环境变量 —— 详见下方的[配置教程](#配置教程)。两个平台都需要把项目根目录设为 `apps/web`（Vercel 一键部署按钮会自动带上；在 Cloudflare 上请把 build root 设为 `apps/web`，构建命令设为 `pnpm --filter @infiplot/web build:cf`）。
 
 ---
 
@@ -134,13 +136,17 @@ InfiPlot 会与四类模型供应商通信。**文本（Text）和视觉（Visio
 
 **2. 填写环境变量**
 
-在 Vercel 项目里设置（**Settings → Environment Variables**），或在本地运行时写进 `apps/web/.env.local`。九个变量为必填；TTS 可选（留空则静音运行）。此外还有一个用于低成本测试的开关：
+九个变量为必填；TTS 可选（留空则静音运行）。此外还有一个用于低成本测试的开关：
 
 | 变量 | 作用 |
 |---|---|
 | `MOCK_IMAGE=true` | 跳过图像生成，渲染器返回一张静态占位图。剧情、语音、选项照常运行。非常适合在不消耗 Runware 额度的情况下调试 TTS。 |
 
-确切的字段格式见 `apps/web/.env.example`。
+在哪里设置（确切字段见 `apps/web/.env.example`）：
+
+- **本地开发** —— `apps/web/.env.local`
+- **Vercel** —— Project Settings → Environment Variables
+- **Cloudflare Workers** —— 在 `apps/web/` 目录下逐个执行 `wrangler secret put <NAME>`，或在 dashboard 里设置（Workers → infiplot → Settings → Variables and Secrets）。如果要给 staging 加访问限制，可以在 Worker 前面挂一个 [Cloudflare Access](https://developers.cloudflare.com/cloudflare-one/applications/)（零代码，邮箱白名单）。
 
 **3. 注意成本**