diff --git a/README.md b/README.md
index ad538ce..0c7fba0 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,39 @@ State is an architectural boundary here, not a preference.
 - **What it is not.** It is not a mail client, not a proxy, and not a relay. It forwards
   metadata to one bot; it does not read arbitrary URLs, open tunnels, or broker traffic.
 
-## 2. 5-minute setup
+## 2. Two ways to run it
+
+One image, one Redis, one SPA. The only difference is what sits in front and which URL you hand
+to Telegram and Stalwart.
+
+| | Form A: backend origin only | Form B: behind the Cloudflare Worker gateway |
+|---|---|---|
+| What answers requests | one backend host | one Worker URL, N backend origins |
+| Failover | none — a down origin stays down | bounded: 2 attempts by default, only timeout and `5xx` retry |
+| Callback URL you register | `https://a.example` | `https://lb.example` |
+| Reachable routes | every route, including `/api/bootstrap` and `/debug/*` | only the 19 safelisted paths |
+| Health to watch | `GET /ready` on the origin | `GET /ready` proxied, plus `GET /healthz-worker` for the gateway aggregate |
+| Extra moving parts | none | one Worker deploy, one origin list |
+| Docs | `docs/deployment.md §2` | `docs/deployment.md §10`, `cloudflare-worker/README.md` |
+
+Pick Form A for a single origin with no HA requirement. Pick Form B for two or more origins, or
+whenever you want one stable callback URL while you roll or rebuild an instance.
+
+Switching is a re-registration, not a migration. Registration is idempotent and registering a
+new address retires the previous subscription, so moving from Form A to Form B, or back, is one
+field in the SPA. Do not register both origins at once: there is a single registration slot, and
+the platform entrance must stay internal (`C-LB-SINGLE-REG-URL`).
+
+No secret moves to the gateway in Form B. It holds no business credential and checks no auth
+header. Instead every backend must carry the same `SAF-AUTH-*` secrets and the same encrypted
+business config, because a callback can land on any instance and no instance can prove it was
+the one asked for (`C-LB-SHARED-SECRETS`). Mis-matched secrets show up as a random 401, not as
+a routing error.
+
+`POST /api/bootstrap` and `/debug/*` stay origin-only in both forms, so neither is exposed
+through the gateway.
+
+## 3. 5-minute setup
 
 Requires a reachable Redis instance and a JMAP session plus a Telegram bot token.
 
@@ -50,9 +82,9 @@ For local builds without Docker: `cargo build --locked` produces the `message-we
 
 If the service answers requests but does nothing useful, check the logs for a startup
 warning: a missing required variable does **not** crash the process. It serves a
-read-only setup router over in-memory state instead. See §3.
+read-only setup router over in-memory state instead. See §4.
 
-## 3. Configuration entry points
+## 4. Configuration entry points
 
 Three layers. They are not interchangeable.
 
@@ -79,7 +111,8 @@ secrets from the environment in normal operation.
 returns 503 until configuration, Redis, and both upstreams (a JMAP session `GET` and
 Telegram `getMe`, 3s each) are reachable. Probe `/ready`, not `/healthz`, when deciding
 whether to route traffic — but `/ready` is the heavier probe (~3s worst case), so a monitor
-that must stay cheap should watch the gateway's aggregated `/healthz`.
+that must stay cheap should watch the gateway aggregate `GET /healthz-worker` when the gateway
+is enabled.
 
 **Remote debug (opt-in, off by default).**
 `/debug/*` is an optional remote-debug surface: live JMAP and Telegram probes, the current
@@ -92,7 +125,7 @@ unset. If you do turn it on for a one-off diagnosis, configure the chat allowlis
 an empty allowlist the test send is not restricted to any chat. See
 `docs/deployment.md` §2.1.
 
-## 4. Security boundary, in one sentence
+## 5. Security boundary, in one sentence
 
 > All state lives in Redis; the process reads only two environment variables and writes
 > nothing to disk.
@@ -103,7 +136,7 @@ startup. It is only compared in constant time, and is never echoed, logged, or s
 Redis ACL password, if you have one, authenticates the Redis connection alone and is not
 the credential for any HTTP endpoint.
 
-## 5. Where to read more
+## 6. Where to read more
 
 | Document | What it answers |
 |---|---|
@@ -113,6 +146,7 @@ the credential for any HTTP endpoint.
 | [`docs/opengaps.md`](docs/opengaps.md) | Gaps, blockers and the next phase |
 | [`docs/retired.md`](docs/retired.md) | What was tried and dropped — abandoned routes, unreleased designs, and names that never existed |
 | [`docs/charter.md`](docs/charter.md) | Project charter: goals, locked technology choices, security invariants, prohibitions, and the stable-ID registry |
+| [`cloudflare-worker/README.md`](cloudflare-worker/README.md) | The Cloudflare Worker gateway: route safelist, timeout and retry budget, bounded failover, health aggregate, deploy |
 | [`AGENTS.md`](AGENTS.md) | Language-agnostic engineering norms: code style, config and secrets, build environment, testing gates, document governance |
 
 Facts that matter are traceable. If two documents disagree, `docs/reference.md` wins.
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 366b4cd..5124a38 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -25,10 +25,34 @@ MessageWeave 位于 JMAP 邮件服务器（例如 Stalwart）与 Telegram bot 
 - **它不是什么。** 它不是邮件客户端，不是代理，也不是转发中继。它只把一个 bot 的元数据
   送达 Telegram；不抓取任意 URL、不开隧道、不中转流量。
 
-## 2. 五分钟跑起来
+## 2. 两种部署形态
+
+同一个镜像、同一个 Redis、同一套 SPA。唯一的区别是前面放什么，以及你把哪个 URL 交给 Telegram 和 Stalwart。
+
+| | 形态 A：仅后端 origin | 形态 B：前置 Cloudflare Worker 网关 |
+|---|---|---|
+| 谁应答请求 | 一个后端主机 | 一个 Worker URL 对 N 个后端 origin |
+| 故障转移 | 没有——origin 挂了就一直挂着 | 有界——默认 2 次尝试，只重试超时与 `5xx` |
+| 你注册的回调 URL | `https://a.example` | `https://lb.example` |
+| 可达路由 | 全部路由，含 `/api/bootstrap` 与 `/debug/*` | 只有 19 个白名单路径 |
+| 要看哪个健康接口 | origin 上的 `GET /ready` | 透传的 `GET /ready`，外加网关聚合 `GET /healthz-worker` |
+| 额外组件 | 无 | 一个 Worker 部署、一份 origin 列表 |
+| 文档 | `docs/deployment.md §2` | `docs/deployment.md §10`、`cloudflare-worker/README.zh-CN.md` |
+
+单 origin 且没有 HA 要求时选形态 A；两个及以上 origin、或想在滚动与重建某个实例时保持一个稳定的回调 URL，就选形态 B。
+
+切换是一次重新注册，不是迁移。注册是幂等的，注册新地址会注销旧订阅，所以从形态 A 换到形态 B（或反过来）只是 SPA 里改一个字段。不要同时注册两个 origin：注册槽只有一个，平台入口必须保持内网（`C-LB-SINGLE-REG-URL`）。
+
+形态 B 里没有任何 secret 搬到网关。它不持有任何业务凭据，也不校验任何认证头。真正要求一致的是每个后端都携带同一组 `SAF-AUTH-*` secret 与同一份加密业务配置——因为回调可能落在任何一个实例上，而任何实例都证明不了自己是被点名的那一个（`C-LB-SHARED-SECRETS`）。凭据不一致表现为随机 401，而不是路由错误。
+
+`POST /api/bootstrap` 与 `/debug/*` 在两种形态下都只保留在 origin 直连，不经过网关暴露。
+
+## 3. 五分钟跑起来
 
 需要可用的 Redis 服务、一个 JMAP session 与一个 Telegram bot token。
 
+这段是**本地容器冒烟测试**。生产部署可以用任何能跑起后端容器、注入加密 secret 并连到外部托管 Redis 的平台，见 `docs/deployment.md` §3 与 `docs/reference.md` 的平台相关部分。
+
 ```sh
 cp .env.example .env           # 填写 REDIS_URL 与 CONFIG_ENCRYPTION_KEY
 docker build -t messageweave:latest .
@@ -42,13 +66,13 @@ docker run --env-file .env -p 8080:8080 messageweave:latest
 不用 Docker 的本地构建：`cargo build --locked` 产出 `message-weave` 二进制。
 
 如果服务有响应但什么都不做，请查看启动日志的告警：**缺少必需变量不会让进程崩溃**，它会
-退化为运行在内存态上的只读配置路由。见 §3。
+退化为运行在内存态上的只读配置路由。见 §4。
 
-## 3. 配置入口
+## 4. 配置入口
 
 共三层，彼此不可替代。
 
-**启动期环境变量 —— 2 个必需，2 个可选。**
+**启动期环境变量 —— 2 个必需，1 个可选。**
 
 | 变量 | 必需 | 默认值 |
 |---|---|---|
@@ -67,7 +91,7 @@ docker run --env-file .env -p 8080:8080 messageweave:latest
 `GET /healthz` 无条件返回 200——它是存活探测，不是就绪探测。`GET /ready` 在配置、Redis 与
 两条上游（JMAP session `GET`、Telegram `getMe`，各 3s）可达之前返回 503。判断是否可路由
 流量时，请探测 `/ready` 而不是 `/healthz`；但 `/ready` 是较重的探针（最坏约 3s），需要
-保持轻量的监控请看网关聚合的 `/healthz`。
+保持轻量的监控在启用网关时请看网关聚合 `GET /healthz-worker`。
 
 **远程联调面（可选，默认关闭）。**
 `/debug/*` 是一套可选的远程联调面：JMAP 与 Telegram 实时探针、当前业务配置，以及单条
@@ -77,13 +101,13 @@ Telegram 发送。它由双因子开关控制——进程必须带 `--debug` **
 设 `DEBUG_TOKEN`。若确实要为一次排障临时开启，请先配好 chat 白名单——白名单为空时，测试
 发送不会受限到任何 chat。见 `docs/deployment.md` §2.1。
 
-## 4. 安全边界，一句话
+## 5. 安全边界，一句话
 
 > 所有状态都在 Redis 里；进程只读两个环境变量，不写任何磁盘。
 
 有一条推论与部署直接相关：SPA 管理凭据——也就是 bootstrap 的信任根——就是 `CONFIG_ENCRYPTION_KEY` 本身，即启动时提供的那个 32 字节 hex 值。它只做常数时间比较，绝不回显、记录或落盘。Redis ACL 密码（如有）只认证 Redis 连接本身，不是任何 HTTP 端点的认证凭据。
 
-## 5. 去哪读更多
+## 6. 去哪读更多
 
 | 文档 | 回答什么 |
 |---|---|
@@ -93,6 +117,7 @@ Telegram 发送。它由双因子开关控制——进程必须带 `--debug` **
 | [`docs/opengaps.zh-CN.md`](docs/opengaps.zh-CN.md) | 缺口、阻塞项与下一阶段目标 |
 | [`docs/retired.zh-CN.md`](docs/retired.zh-CN.md) | 试过但没用的：废弃路线、未落地的设计与从未存在的名字 |
 | [`docs/charter.zh-CN.md`](docs/charter.zh-CN.md) | 项目章程：项目目标、锁定的技术选型、安全不变量、禁止事项与稳定 ID 注册表 |
+| [`cloudflare-worker/README.zh-CN.md`](cloudflare-worker/README.zh-CN.md) | Cloudflare Worker 网关：路由白名单、超时与重试预算、有界故障转移、健康聚合、部署 |
 | [`AGENTS.md`](AGENTS.md) | 语言无关的工程规范：代码风格、配置与密钥、构建环境、测试门禁、文档治理 |
 
 重要的事实都可追溯。两份文档不一致时，以 `docs/reference.md` 为准。
diff --git a/cloudflare-worker/README.md b/cloudflare-worker/README.md
index 2ced1fd..99e8494 100644
--- a/cloudflare-worker/README.md
+++ b/cloudflare-worker/README.md
@@ -1,120 +1,295 @@
-# MessageWeave Cloudflare Worker（ARCH-LB-WORKER）
+# MessageWeave Cloudflare Worker gateway
 
-统一 HTTPS 入口 + 多后端 origin 故障转移（HA/LB 子项目）。
-**透传模型**：Worker 不感知业务，原样转发请求到多个 https 后端 origin；仅「超时 / 5xx」做有界故障转移。
+> [中文版本 / Chinese version → README.zh-CN.md](README.zh-CN.md)
 
-> 本组件是 **safelist 受限的边缘负载均衡器（edge load balancer）**：路由固定 18 条白名单、
-> 后端 origin 在部署期固定且仅允许 https、未知路径一律 404。它只对固定后端做请求转发与
-> 故障转移，不接受任意目标主机，也不提供任何形式的流量中转或访问隐藏能力。
+This is the canonical English version. The Chinese version is
+[README.zh-CN.md](README.zh-CN.md).
 
-> 设计依据：`docs/design.md §10 / NFR-HA-MULTI-INSTANCE`、`docs/deployment.md §10`。
-> 安全基线与禁止事项：`docs/charter.md §3/§5`（稳定 ID 注册表 §8）。
+One public HTTPS entry point in front of one or more MessageWeave backends, with bounded
+multi-origin failover (HA/LB sub-project). **Pass-through model**: the Worker does not parse
+business payloads and forwards the request as-is to the backend https origins; only *timeout /
+5xx* triggers a bounded failover to another instance.
 
-## 目录
+> This component is a **safelist-restricted edge load balancer**: the route set is fixed (19
+> whitelisted paths), the backend origins are fixed at deploy time and https-only, and every
+> unknown path gets a `404`. It only forwards requests to those fixed backends and fails over
+> between them. It does not accept an arbitrary target host and provides no general-purpose
+> traffic-relay or access-hiding capability.
 
-- `wrangler.toml` — Wrangler 示例配置（name/main/compat/vars；后端 secret 走 `wrangler secret`）
-- `src/index.js` — Worker 入口（路由分发、/healthz-worker 聚合、safelist 校验）
-- `src/backends.js` — origin 解析 + https/凭据/query 校验（C-HTTPS-INBOUND）
-- `src/lb.js` — 透传转发 + 有界故障转移（SAF-LB-PASSTHRU）
-- `src/health.js` — 健康聚合探针（MOD-HEALTH-AGG / C-NO-DB）
-- `test/*.test.js` — 单元/集成测试（零依赖，`node --test`）
-- `package.json` — npm 元数据（`dev`/`deploy` 调 wrangler；`test` 纯 node）
+> Design basis: `docs/design.md §11.3` (`NFR-HA-MULTI-INSTANCE`) and `docs/deployment.md §10`.
+> Security baseline and prohibitions: `docs/charter.md §3`, `docs/charter.md §5`; stable-ID
+> registry `docs/charter.md §8`.
 
-## 零依赖设计
+## 1. What it is, and what it is not
 
-运行时仅依赖 ES2022 标准 + 平台/Node 的 `fetch`/`Headers`/`Request`/`Response`/`URL`。
-`npm run test` 直接 `node --test test/`，**无需安装**任何生产依赖；
-`wrangler` 仅在 `check`/`deploy`/`dev` 中作 devDependency（CI 可选装）。
+- **Forward only.** Method, headers (including auth headers) and body are forwarded as-is. The
+  Worker performs no authentication of its own and rewrites nothing.
+- **Secretless.** No Telegram bot token, no JMAP password, no session secret. It forwards
+  whatever auth header it is given and checks none of them. All backends must instead share
+  the same set of `SAF-AUTH-*` secrets — `RECONCILE_TOKEN`, `TG_WEBHOOK_SECRET` and the
+  encrypted business config — because a callback can land on any instance and no instance can
+  prove which one was asked (`C-LB-SHARED-SECRETS`). Per-instance secrets mean a random 401.
+- **No origin discovery.** Origins come from the deploy-time origin list only.
+- **Zero runtime dependencies.** Pure ES2022 plus the platform `fetch`, `Headers`, `Request`,
+  `Response` and `URL`. `wrangler` is a devDependency, used only by `check`, `deploy` and
+  `dev`.
+- **Zero state.** No Redis, no JMAP, no database (`C-NO-DB`, `C-REDIS-ONLY-STATE`). The only
+  mutable state is an in-isolate health probe cache.
+- **No long-lived connections** (`C-NO-LONG-CONN`). Pure request-response. The request body is
+  read once as `arrayBuffer` and re-attached on every attempt, so streaming is never required.
+- **Not a queue.** There is no retry beyond the bounded attempts below. When every origin
+  fails the gateway answers `503`, and Telegram / Stalwart redelivery is what makes up for it.
 
-## 语义
+## 2. Directory layout
 
-### 透传（A，SAF-LB-PASSTHRU）
-- 原样转发 method / headers（含鉴权头）/ body；不鉴权改写。
-- 所有后端实例共享同一组 secret（`C-LB-SHARED-SECRETS`）：同一 `TELEGRAM_WEBHOOK_SECRET`、
-  `JMAP_PUSH_VERIFICATION_CODE`、`API_TOKEN`（`API_TOKEN` 在 `docs/deployment.md` §10 仅用于多实例互斥，非鉴权）
-  + 相同 App Password（各后端实例的 `JMAP` 可不同，`docs/deployment.md` §10.2）。
+| file | role |
+|---|---|
+| `wrangler.toml` | `name`, `main`, compatibility flags, `[vars]` |
+| `package.json` | `check` / `test` / `deploy` / `dev` scripts only, no runtime dependencies |
+| `src/index.js` | entry point: HTTPS redirect, route dispatch, safelist, health aggregate |
+| `src/backends.js` | origin parsing and validation, route safelist |
+| `src/lb.js` | pass-through forwarding and bounded failover |
+| `src/health.js` | TTL-cached health aggregate probe |
+| `test/*.test.js` | 38 tests in four files, all offline |
 
-### 路由 safelist（ARCH-LB-WORKER / C-LB-SINGLE-REG-URL）
-- HTTP requests receive a permanent `308` redirect to the same HTTPS URL before route validation or forwarding.
-- 透传公开 `GET /api/status` 启动状态，以及管理 SPA API：`POST /api/admin/session[/revoke]`、`GET|PUT /api/enabled`（业务总开关，SPA 服务卡片读写）、`GET|PUT /api/config`、`GET|PUT /api/business-config`（读回 + 增量保存）、`POST /api/business-config/preflight`（保存前逐组件连通性预检）。启动状态只包含缺少的环境变量名称；管理 API 的鉴权仍由后端执行。
-- 只透传 `POST /webhook/tg`、`POST /push/jmap`、`POST /api/push/register`、`POST /api/telegram/register-webhook`、`POST /api/push/disable`、`POST /reconcile`、`POST /worker`、`GET /ready`。
-- 其它路径 → **404**（不透传，避免 Worker 沦为后端任意路径的跳板）。
-- method 不符 → **405**。
+## 3. Pass-through semantics
 
-### 有界故障转移（`docs/deployment.md` §10.4）
-- 每次请求只试 `min(LB_MAX_ATTEMPTS, origins.length)` 次；默认 2（首次 + 1 次换实例）。
-- **仅** 超时（AbortError）或 5xx 触发换下一个实例；4xx / 2xx / 3xx 直接返回。
-- 起点按 `rng` 随机化（默认 `Math.random`），实现双活分摊；单 origin 配置时退化为确定性。
-- 全失败 → **503 All Backends Unavailable**（交由 Telegram / Stalwart 自动重投兜底，不丢消息）。
-- 健康缓存（`aggregateHealth` / `LB_HEALTH_TTL_MS`）仅服务于 `/healthz-worker` 聚合视图；转发目前**不做健康路由过滤**（`docs/deployment.md` §10.4「只向健康实例转发」为后续增强，当前靠故障转移兜底）。
-- **例外：`POST /reconcile` 与 `POST /worker` 走 per-route 覆盖。** 两者都是后端同步长任务：
-  全局 10s 超时会把它们误判为失败并故障转移到第二实例，而第二实例对 `/reconcile` 必然立刻
-  返回 409（集群级锁 `lock:reconcile`，初租 300s 由心跳续期），对 `/worker` 只会重复排同一批
-  消息。所以这两条路由改为：超时分别取 `LB_RECONCILE_TIMEOUT_MS`（默认 `320000`，留足锁初租 +
-  心跳余量）与 `LB_WORKER_TIMEOUT_MS`（默认 `300000`，等于后端单条事件下界），且 `maxAttempts=1`
-  绝不故障转移。其余快路径保持全局默认。
+- Method, headers and body go out unchanged; the backend response status, body and headers are
+  returned as-is.
+- The only header the gateway adds is best-effort observability: `x-lb-backend`, naming the
+  origin that answered. The write sits behind a `try/catch`. A cross-origin response that
+  carries no `access-control-allow-*` header comes back with an immutable header guard, and
+  `headers.set` throws on those. An observability write that throws must never mask a healthy
+  `2xx` as a `503`, so the header is dropped silently when it cannot be written. That exact
+  defect was the 2026-09-30 production incident.
+- `GET` and `HEAD` never forward a body: a bodyless upstream response is returned as it is,
+  and no `Content-Length` is recomputed.
+- Backend `3xx` redirects are followed by the gateway itself (`redirect: "follow"`), so a
+  redirecting origin never hands the browser a second hop.
+- Logs and error strings carry method, path, origin and failure class only. Never headers,
+  body, auth secrets or App Password (`SAF-LOG-PURITY`).
 
-### 健康聚合（MOD-HEALTH-AGG；C-NO-DB / C-REDIS-ONLY-STATE）
-- `GET /healthz-worker`（由 Worker 自身承载；入站 `/healthz` 保留给源站自己的健康检查并透传，两者互不遮蔽）：
-  按 TTL 缓存（默认 30s）探测各后端 `/healthz`，返回
-  `{status: ok|down, version, available, total, backends:[{origin, up, status}]}`；
-  有 ≥1 后端 up → 200；全部 down → 503。
-- **不代理 Redis/JMAP**：Worker 不做数据库侧检查；后端端到端就绪（配置完整性 + Redis 可达 + JMAP session + Telegram getMe，对应 `ARCH-READY-BASELINE`）由 `/ready`（透传）承担。
+## 4. Route safelist
 
-### 无长连接 / 无密钥日志（§3/§5 红线）
-- 不使用 WebSocket/SSE/长轮询（`C-NO-LONG-CONN`）：纯请求-响应转发，body 一次性 `arrayBuffer` 回灌。
-- 日志只打「方法 / 路径 / origin / 失败类别」；**绝不**打印 header / body / 鉴权 secret / App Password（`SAF-LOG-PURITY`）。
+Every inbound **HTTP** request gets a permanent **308** redirect to the same HTTPS URL before
+route validation or forwarding (`C-HTTPS-INBOUND`). After that the request must hit one of 19
+paths and carry a method that path allows; every other combination is refused at the edge.
 
-## 环境变量
+| path | methods |
+|---|---|
+| `/` | GET |
+| `/assets/config.js` | GET |
+| `/assets/styles.css` | GET |
+| `/api/status` | GET |
+| `/api/config` | GET PUT |
+| `/api/business-config` | GET PUT |
+| `/api/business-config/preflight` | POST |
+| `/api/admin/session` | POST |
+| `/api/admin/session/revoke` | POST |
+| `/api/enabled` | GET PUT |
+| `/webhook/tg` | POST |
+| `/push/jmap` | POST |
+| `/api/push/register` | POST |
+| `/api/telegram/register-webhook` | POST |
+| `/api/push/disable` | POST |
+| `/reconcile` | POST |
+| `/worker` | POST |
+| `/healthz` | GET |
+| `/ready` | GET |
 
-| 变量 | 必填 | 说明 |
-|---|---|---|
-| `BACKEND_ORIGINS_JSON` | 是 | JSON 数组，形如 `["https://a.platform1.example","https://b.platform2.example"]`；必须全部 https、无内嵌凭据/query/fragment/路径。已写在 `wrangler.toml` 的 `[vars]`。 |
-| `LB_REQUEST_TIMEOUT_MS` | 否 | 单 origin 请求超时；默认 `10000`。建议 > 最坏 cold start + 最长 JMAP 拉取。 |
-| `LB_MAX_ATTEMPTS` | 否 | 每请求最多 origin 尝试次数；默认 `2`（= 1 次故障转移）。`POST /reconcile` 与 `POST /worker` 固定为 `1`。 |
-| `LB_RECONCILE_TIMEOUT_MS` | 否 | 仅 `POST /reconcile` 的单 origin 超时覆盖；默认 `320000`（须大于后端锁初租 300s + 心跳余量）。 |
-| `LB_WORKER_TIMEOUT_MS` | 否 | 仅 `POST /worker` 的单 origin 超时覆盖；默认 `300000`（= 后端单条事件下界 `SINGLE_EVENT_CEILING_FLOOR_MS`）。一次排空 batch 条（默认 10，硬上限 10），batch 拉大时需相应上调。 |
-| `LB_HEALTH_TTL_MS` | 否 | 健康探测缓存 TTL；默认 `30000`。 |
-| `LB_VERSION` | 否 | `/healthz-worker` 响应体里的 `version` 字段，用于确认线上是哪次部署在回答；取自 `wrangler.toml` 的 `[vars]`（当前 `2026.10.4`），改 LB 逻辑的提交同时 bump |
+- Unknown path: `404`, body `route not forwarded: <path>`. The gateway can therefore never be
+  turned into a jump host for arbitrary backend paths.
+- Method mismatch on a known path: `405`, body `method not allowed for <path>`, plus an
+  `Allow` header.
+- Bootstrap (`POST /api/bootstrap`) and the remote diagnostics face (`/debug/*`) are
+  deliberately absent, so both stay origin-only.
+- `/healthz-worker` is not in the safelist at all: the gateway serves it itself, on `GET`
+  only.
 
-> 默认写在 `wrangler.toml` 的 `[vars]`（**明文例外**，因为当前值只是公开可达的 https origin，
-> 不是凭据）。一旦要放内网地址、带内嵌凭据的 URL、或不想公开的 staging 主机名，
-> 立刻改用 `npx wrangler secret put BACKEND_ORIGINS_JSON` 并把该行从 `[vars]` 删掉。
+## 5. Timeout and retry budget
 
-## 本地 / CI 验证
+| variable | required | default | applies to |
+|---|---|---|---|
+| `BACKEND_ORIGINS_JSON` | yes | — | all routes |
+| `LB_REQUEST_TIMEOUT_MS` | no | `10000` | every route except the two below, and the §7.2 probe |
+| `LB_MAX_ATTEMPTS` | no | `2` | attempts per request |
+| `LB_RECONCILE_TIMEOUT_MS` | no | `320000` | `POST /reconcile` only |
+| `LB_WORKER_TIMEOUT_MS` | no | `300000` | `POST /worker` only |
+| `LB_HEALTH_TTL_MS` | no | `30000` | `/healthz-worker` probe cache only |
+| `LB_VERSION` | no | `unknown` | `/healthz-worker` `version` field |
+
+Integer env values are parsed with `Math.floor`. A non-finite or non-positive value is ignored
+and the default applies, so a typo cannot switch the budget off.
+
+`/reconcile` and `/worker` are **single-attempt routes** with per-route timeout overrides.
+Both are long synchronous backend jobs: at the 10 s global timeout the gateway would declare
+them failed and fail over to a second instance, but that instance answers `/reconcile` with
+`409` immediately (the cluster-wide `lock:reconcile` starts with a 300 s lease, renewed by
+heartbeat) and a second `/worker` would merely drain the same batch twice. They therefore get
+`LB_RECONCILE_TIMEOUT_MS` (default 320 s, headroom over the 300 s lease plus heartbeats) and
+`LB_WORKER_TIMEOUT_MS` (default 300 s, equal to the backend per-event floor
+`SINGLE_EVENT_CEILING_FLOOR_MS`), both with `max_attempts = 1`.
+
+`LB_WORKER_TIMEOUT_MS` must grow if the `/worker` batch grows: the backend batch default and
+its hard cap are both 10.
+
+## 6. Bounded failover
+
+- Each request tries `max(1, min(LB_MAX_ATTEMPTS, origins.length))` origins. The default of
+  2 is one first attempt plus one failover.
+- Only a timeout or a `5xx` response moves on to the next origin. `2xx`, `3xx` and `4xx` are
+  answers and are returned immediately.
+- A timeout or transport failure counts as retryable when the error name is `AbortError`, or
+  when the message, or the message of a `cause` further down the chain, matches one of:
+  `fetch failed`, `network error`, `socket hang up`, `ECONNREFUSED`, `ECONNRESET`,
+  `EAI_AGAIN`, `ENOTFOUND`, `ETIMEDOUT`, `EHOSTUNREACH`, `ENETUNREACH`. Anything else fails
+  fast.
+- With more than one origin and more than one attempt, the starting origin is chosen with
+  `rng` (defaulting to `Math.random`) so load spreads over the healthy instances. A single
+  origin degrades to a fixed order.
+- Every origin fails: `503` with status text `All Backends Unavailable` and body
+  `all backends failed: <last reason>`. Telegram and Stalwart then redeliver, which is why
+  nothing is lost.
+
+The health cache feeds only the `/healthz-worker` aggregate view. Forwarding does **not**
+filter by health; today, failover is the safety net.
+
+## 7. Health endpoints
+
+The two endpoints deliberately do not overlap, so neither can hide the other.
+
+### 7.1 GET /healthz — passthrough
+
+Forwarded like any other safelisted route. The response is the backend's own liveness
+envelope, which is exactly why it can read healthy while a different origin is down.
+
+### 7.2 GET /healthz-worker — gateway aggregate
+
+Answered by the gateway itself. It never touches the forwarded route set.
+
+- Probes each origin's `/healthz` with the same request timeout as forwarding
+  (`LB_REQUEST_TIMEOUT_MS`, default 10 s). Redirects are followed, so an origin that answers
+  with a `3xx` still counts as up.
+- `up` is true when the origin answered with a status below 500. A probe failure records
+  `up: false` with `status: null`.
+- Results are cached per origin for `LB_HEALTH_TTL_MS` (default 30 s) in an in-isolate map,
+  to keep probe traffic bounded. A cache miss probes and stores; a fresh entry is served
+  without another probe.
+- Response body: `{status, version, available, total, backends: [{origin, up, status}]}`.
+  - at least one origin up: HTTP `200`, `status: "ok"`
+  - every origin down: HTTP `503`, `status: "down"`
+  - no origins configured: HTTP `200`, `status: "no-backends"`
+  - `version` is `LB_VERSION`, defaulting to the literal string `unknown`
+- Any method other than `GET`: `405` with `Allow: GET`.
+- The gateway does not proxy Redis or JMAP readiness. End-to-end backend readiness
+  (`ARCH-READY-BASELINE`: config completeness, Redis reachable, JMAP session, Telegram
+  `getMe`) stays on the backend's `/ready`, which is passed through.
+
+## 8. Callback registration
+
+The SPA registers callback URLs against **one** origin (`C-LB-SINGLE-REG-URL`). Origin only,
+no path:
+
+- Gateway enabled: the Worker URL, for example `https://lb.example`.
+- Gateway disabled: a backend origin, for example `https://a.example`.
+
+Whichever origin you register is where `/webhook/tg` and `/push/jmap` land. All three
+registration endpoints are safelisted and pass through the gateway, so registration works
+through either front door. Registration is idempotent, and registering a new address retires
+the previous subscription — that is how you switch fronts.
+
+## 9. Configuration
+
+- Defaults live in `wrangler.toml` `[vars]` as a **deliberate plaintext exception**: the
+  current value is only publicly reachable https origins, which is not a credential. The
+  moment you need an internal address, a URL with embedded credentials, or a hostname that
+  should not be public, move it to `npx wrangler secret put BACKEND_ORIGINS_JSON` and delete
+  the line from `[vars]`. Git history is irreversible, so deleting it does not un-publish it.
+- `BACKEND_ORIGINS_JSON` is a JSON **array of plain strings**. Object shapes such as
+  `{"url": "..."}` are rejected: `parseBackendOrigins` throws, and because the config is
+  re-parsed on **every** request the failure shows up as `503` on every request rather than
+  at boot. The body is `misconfigured backends`. An empty list throws the same way, before
+  anything is forwarded.
+- Each entry must be an https **origin** only: no http, no path, no query, no fragment, no
+  embedded credentials (`C-HTTPS-INBOUND`).
+- `wrangler.toml` also pins `name = "messageweave-lb"`, `main = "src/index.js"`,
+  `compatibility_date = "2025-01-01"` and
+  `compatibility_flags = ["nodejs_compat_v2"]`. `nodejs_compat_v2` is what lets the test
+  files import `node:test` and `node:assert/strict`. The runtime code imports no
+  node module.
+- Comments in `wrangler.toml` must stay single-line `#` comments. TOML has no block comment,
+  so a JSDoc `/** */` block makes wrangler fail to parse the file at all.
+
+## 10. Local and CI verification
 
 ```bash
 cd cloudflare-worker
 
-# 单元/集成测试（零依赖）：
-npm run test
-# 等价：node --test test/
-
-# 语法检查 + wrangler dry-run（需 npx wrangler，会拉 devDependency）：
-npm run check
-# 等价：node --check src/*.js && node --check test/*.test.js && wrangler deploy --dry-run
+npm test       # 38 tests, four files, fully offline
+npm run check  # node --check on sources and tests, then wrangler deploy --dry-run
 ```
 
-## 部署示例
+`npm test` is `node --test`, which picks up `test/*.test.js`: `test/index.test.js` 15,
+`test/lb.test.js` 12, `test/backends.test.js` 6, `test/health.test.js` 5. There is no install
+step for the tests — the Worker has no runtime dependencies, and the test files import only
+`node:test` and `node:assert/strict`.
+
+Two traps:
+
+- `node --test test/` (a directory) exits 0 after running **zero** tests on some Node
+  versions. Always pass the file glob.
+- A default CI install step of `bun install` ignores the npm lockfile: it re-resolves and can
+  move wrangler across major versions. Add an explicit `npm ci` before the test step if you
+  need the pinned wrangler.
+
+## 11. Deploy
 
 ```bash
 cd cloudflare-worker
-# 安装 dev dep（仅 wrangler）：
 npm install --no-audit --no-fund
-# BACKEND_ORIGINS_JSON 已写在 wrangler.toml 的 [vars]，直接部署：
-npx wrangler deploy
-# 可选调参（默认值已够用；要覆盖就用 dashboard 的 Add Variable）：
-#   LB_REQUEST_TIMEOUT_MS / LB_MAX_ATTEMPTS / LB_HEALTH_TTL_MS
-#   LB_RECONCILE_TIMEOUT_MS / LB_WORKER_TIMEOUT_MS
-# 仅当 [vars] 里要放非公开值时才改用 secret 注入：
-npx wrangler secret put BACKEND_ORIGINS_JSON
-# 部署后确认：
-curl https://<your-worker>.workers.dev/healthz
+npm run deploy
+curl https://<your-worker>.workers.dev/healthz-worker
 ```
 
-健康探针：
+`npm run check` includes `wrangler deploy --dry-run --outdir=.build-check`, which bundles the
+four sources and reports the artifact size before anything is published. The gateway is
+deployed from push, so a `curl` of `/healthz-worker` and a compare of its `version` is the
+acceptance check. Bump `LB_VERSION` in the same commit as any LB logic change, so you can tell
+which build answered.
 
-```bash
-curl https://lb.messageweave.example/healthz
-# => {"status":"ok","available":2,"total":2,"backends":[{"origin":"https://a.example","up":true,"status":200},...]}
-```
+Two production incidents worth keeping in mind:
+
+- **2026-09-30**: a build wrote `x-lb-backend` onto proxied responses. Cross-origin responses
+  without `access-control-allow-*` headers have an immutable header guard, so `headers.set`
+  threw and the surrounding handler logged a healthy backend as unavailable and burned its
+  retries — the gateway returned `503` while `GET /` actually returned `200`.
+  `/healthz-worker` did not go through that code path, which is exactly what hid the outage.
+  Fixed by making the header write best-effort.
+- **Object-shaped origin lists fail silently at parse time.** `parseBackendOrigins` throws and
+  you get `503 misconfigured backends` on every request. Keep `weight` and any other
+  per-origin tuning out of the list: nothing reads them.
+
+## 12. Design invariants
+
+- `SAF-LB-PASSTHRU` — no auth, header or body rewriting on the path
+- `C-HTTPS-INBOUND` — https-only origins, embedded credentials and paths rejected, HTTP gets a
+  308
+- `C-LB-SINGLE-REG-URL` — one callback origin, unknown paths 404
+- `C-LB-SHARED-SECRETS` — every backend carries identical business credentials
+- `MOD-HEALTH-AGG` — TTL-cached aggregate probe owned by the gateway
+- `C-NO-DB`, `C-REDIS-ONLY-STATE` — no database or Redis access from the gateway
+- `C-NO-LONG-CONN` — request-response only
+- `ARCH-READY-BASELINE` — end-to-end readiness stays on the backend's `/ready`
+- `SAF-LOG-PURITY` — method, path, origin and failure class only
+- `ARCH-LB-WORKER` — the gateway is the only edge component
+- `NFR-HA-MULTI-INSTANCE` — multi-origin failover is how HA is realised
+
+## References
+
+- `docs/deployment.md §10` — gateway deployment, configuration and rollout
+- `docs/reference.md §4` — gateway versus backend route matrix
+- `docs/reference.md §9.2` — backend configuration and secrets
+- `docs/reference.md §9.4` — health and release checks
+- `docs/design.md §11.3` — HA and multi-instance design
+- `docs/charter.md §3`, `docs/charter.md §5`, `docs/charter.md §8` — security baseline,
+  prohibitions, stable-ID registry
diff --git a/cloudflare-worker/README.zh-CN.md b/cloudflare-worker/README.zh-CN.md
new file mode 100644
index 0000000..64d746c
--- /dev/null
+++ b/cloudflare-worker/README.zh-CN.md
@@ -0,0 +1,194 @@
+# MessageWeave Cloudflare Worker 网关
+
+> [English version / 英文版 → README.md](README.md)
+
+面向一个或多个 MessageWeave 后端的统一 HTTPS 入口，带**有界多 origin 故障转移**（HA/LB 子项目）。**透传模型**：Worker 不解析业务载荷，把请求原样转发给后端 https origin；只有*超时 / 5xx* 才触发有界的故障转移到另一个实例。
+
+> 本组件是**基于白名单限制的边缘负载均衡器**：路由集合固定（19 个白名单路径）、后端 origin 在部署时固定且仅允许 https、任何未知路径一律 `404`。它只把这些固定后端之间的请求做转发与故障转移，不接受任意目标主机，也不提供任何通用的流量中转或隐身能力。
+
+> 设计依据：`docs/design.md §11.3`（`NFR-HA-MULTI-INSTANCE`）与 `docs/deployment.md §10`。
+> 安全基线与禁令：`docs/charter.md §3`、`docs/charter.md §5`；稳定 ID 注册表 `docs/charter.md §8`。
+
+## 1. 它是什么，不是什么
+
+- **只转发。** method、headers（含认证头）、body 一律原样转发。Worker 自身不做任何认证，也不改写任何内容。
+- **无 secret。** 没有 Telegram bot token，没有 JMAP 密码，没有 session secret。它收到什么认证头就转发什么，自己一个都不校验。真正共享的是后端之间必须一致的同一组 `SAF-AUTH-*` secret——`RECONCILE_TOKEN`、`TG_WEBHOOK_SECRET` 与加密后的业务配置——因为回调可能落在任何一个实例上，而任何实例都证明不了自己是被点名的那一个（`C-LB-SHARED-SECRETS`）。凭据不一致的表现是随机 401，而不是路由错误。
+- **不做 origin 发现。** origin 只来自部署时的 origin 列表。
+- **零运行时依赖。** 纯 ES2022 加平台提供的 `fetch`、`Headers`、`Request`、`Response`、`URL`。`wrangler` 是 devDependency，只用于 `check`、`deploy`、`dev`。
+- **零状态。** 不连 Redis、不连 JMAP、不连数据库（`C-NO-DB`、`C-REDIS-ONLY-STATE`）。唯一的可变状态是 isolate 内的健康探测缓存。
+- **无长连接**（`C-NO-LONG-CONN`）。纯请求-响应。请求体只读一次为 `arrayBuffer`，每次尝试重新挂上去，因此不需要流式。
+- **不是队列。** 除了下面那几轮有界尝试，不做任何重试。所有 origin 都失败时网关返回 `503`，靠 Telegram / Stalwart 的自身重投兜底。
+
+## 2. 目录结构
+
+| 文件 | 职责 |
+|---|---|
+| `wrangler.toml` | `name`、`main`、compatibility flags、`[vars]` |
+| `package.json` | 只有 `check` / `test` / `deploy` / `dev` 脚本，无运行时依赖 |
+| `src/index.js` | 入口：HTTPS 重定向、路由分发、白名单、健康聚合 |
+| `src/backends.js` | origin 解析与校验、路由白名单 |
+| `src/lb.js` | 透传转发与有界故障转移 |
+| `src/health.js` | 带 TTL 的健康聚合探测 |
+| `test/*.test.js` | 四个文件共 38 条测试，全部离线 |
+
+## 3. 透传语义
+
+- method、headers、body 原样发出；后端响应的 status、body、headers 原样返回。
+- 网关唯一新增的 header 是尽力而为的观测头：`x-lb-backend`，标记应答的 origin。写入放在 `try/catch` 里。跨域且不带 `access-control-allow-*` 的响应，其 header guard 是 immutable，`headers.set` 会抛异常。一次会抛异常的观测写入绝不能把健康的 `2xx` 掩盖成 `503`，所以写不进去时静默放弃该 header。这个缺陷就是 2026-09-30 的生产事故根因。
+- `GET` 和 `HEAD` 不带 body 转发：上游没有 body 的响应直接原样返回，不重算 `Content-Length`。
+- 后端的 `3xx` 由网关自己跟随（`redirect: "follow"`），跳转型的 origin 不会把第二跳甩给浏览器。
+- 日志与错误串只包含 method、path、origin、失败类别，绝不含 headers、body、认证 secret 或 App Password（`SAF-LOG-PURITY`）。
+
+## 4. 路由白名单
+
+所有入站 **HTTP** 请求先被永久 **308** 重定向到同一个 HTTPS URL，之后才做路由校验与转发（`C-HTTPS-INBOUND`）。此后请求必须命中 19 个路径之一且 method 匹配，其余组合一律在边缘拒绝。
+
+| 路径 | 允许的 method |
+|---|---|
+| `/` | GET |
+| `/assets/config.js` | GET |
+| `/assets/styles.css` | GET |
+| `/api/status` | GET |
+| `/api/config` | GET PUT |
+| `/api/business-config` | GET PUT |
+| `/api/business-config/preflight` | POST |
+| `/api/admin/session` | POST |
+| `/api/admin/session/revoke` | POST |
+| `/api/enabled` | GET PUT |
+| `/webhook/tg` | POST |
+| `/push/jmap` | POST |
+| `/api/push/register` | POST |
+| `/api/telegram/register-webhook` | POST |
+| `/api/push/disable` | POST |
+| `/reconcile` | POST |
+| `/worker` | POST |
+| `/healthz` | GET |
+| `/ready` | GET |
+
+- 未知路径：`404`，body 为 `route not forwarded: <path>`。因此网关永远不可能被当作跳板去访问后端的任意路径。
+- 路径已知但 method 不匹配：`405`，body 为 `method not allowed for <path>`，并附带 `Allow` header。
+- 引导接口（`POST /api/bootstrap`）与远程诊断面（`/debug/*`）刻意不在白名单内，两者都只保留在 origin 直连。
+- `/healthz-worker` 完全不在白名单里：它由网关自己应答，且只接受 `GET`。
+
+## 5. 超时与重试预算
+
+| 变量 | 必填 | 默认值 | 适用范围 |
+|---|---|---|---|
+| `BACKEND_ORIGINS_JSON` | 是 | — | 所有路由 |
+| `LB_REQUEST_TIMEOUT_MS` | 否 | `10000` | 除下面两条外的所有路由，以及 §7.2 的探测 |
+| `LB_MAX_ATTEMPTS` | 否 | `2` | 每请求的尝试次数 |
+| `LB_RECONCILE_TIMEOUT_MS` | 否 | `320000` | 仅 `POST /reconcile` |
+| `LB_WORKER_TIMEOUT_MS` | 否 | `300000` | 仅 `POST /worker` |
+| `LB_HEALTH_TTL_MS` | 否 | `30000` | 仅 `/healthz-worker` 探测缓存 |
+| `LB_VERSION` | 否 | `unknown` | `/healthz-worker` 的 `version` 字段 |
+
+整数型 env 值用 `Math.floor` 解析。非有限数或非正值会被忽略并回落到默认值，所以手滑不会把预算关掉。
+
+`/reconcile` 与 `/worker` 是**单次尝试路由**，各自有独立的超时覆盖。两者都是后端耗时的同步长任务：按全局 10 s 超时，网关会判定它们失败并故障转移到第二个实例，但第二个实例对 `/reconcile` 会立刻返回 `409`（集群级 `lock:reconcile` 初始租约 300 s，靠心跳续租），而第二个 `/worker` 只会把同一批消息再排一遍。所以这两条路由拿到 `LB_RECONCILE_TIMEOUT_MS`（默认 320 s，比 300 s 租约加心跳多留余量）与 `LB_WORKER_TIMEOUT_MS`（默认 300 s，等于后端单条事件地板 `SINGLE_EVENT_CEILING_FLOOR_MS`），并且都是 `max_attempts = 1`。
+
+如果 `/worker` 的批大小上调，`LB_WORKER_TIMEOUT_MS` 必须跟着加：后端批量的默认值与硬上限都是 10。
+
+## 6. 有界故障转移
+
+- 每个请求尝试 `max(1, min(LB_MAX_ATTEMPTS, origins.length))` 个 origin。默认 2 即首次加一次故障转移。
+- 只有超时或 `5xx` 才会换下一个 origin。`2xx`、`3xx`、`4xx` 都是应答，立即原样返回。
+- 超时与网络层失败被判为可重试的条件：错误 name 是 `AbortError`，或消息、或 `cause` 链上更深的错误消息命中 `fetch failed`、`network error`、`socket hang up`、`ECONNREFUSED`、`ECONNRESET`、`EAI_AGAIN`、`ENOTFOUND`、`ETIMEDOUT`、`EHOSTUNREACH`、`ENETUNREACH`。其余一律 fail-fast。
+- 当 origin 大于 1 且尝试次数大于 1 时，起点 origin 由 `rng` 决定（默认 `Math.random`），把负载摊到健康实例上；单个 origin 退化为固定顺序。
+- 所有 origin 都失败：`503`，status text 为 `All Backends Unavailable`，body 为 `all backends failed: <last reason>`。随后由 Telegram 与 Stalwart 重投，消息因此不丢。
+
+健康缓存只服务于 `/healthz-worker` 的聚合视图。转发路径**不**按健康过滤；现阶段故障转移就是安全网。
+
+## 7. 健康接口
+
+两个接口刻意不重叠，谁都不能掩盖谁。
+
+### 7.1 GET /healthz — 透传
+
+与其他白名单路由一样被转发。响应是后端自己的 liveness envelope，这也正是它在另一个 origin 已挂时依然显示健康的原因。
+
+### 7.2 GET /healthz-worker — 网关聚合
+
+由网关自己应答，完全不接触被转发的路由集合。
+
+- 用与转发同源的请求超时（`LB_REQUEST_TIMEOUT_MS`，默认 10 s）探测每个 origin 的 `/healthz`。重定向会被跟随，所以返回 `3xx` 的 origin 同样计为 up。
+- origin 应答状态码低于 500 即为 `up`。探测失败记 `up: false` 且 `status: null`。
+- 结果按 origin 缓存 `LB_HEALTH_TTL_MS`（默认 30 s）在 isolate 内的 map 中，用来控制探测流量。未命中就探测并写入；未过期的缓存直接返回，不再探测。
+- 响应体：`{status, version, available, total, backends: [{origin, up, status}]}`。
+  - 至少一个 origin 在线：HTTP `200`，`status: "ok"`
+  - 全部 origin 离线：HTTP `503`，`status: "down"`
+  - 未配置 origin：HTTP `200`，`status: "no-backends"`
+  - `version` 即 `LB_VERSION`，未配置时为字面量 `unknown`
+- 任何非 `GET` 的 method：`405`，并带 `Allow: GET`。
+- 网关不代理 Redis 或 JMAP 的 readiness。端到端后端就绪判定（`ARCH-READY-BASELINE`：配置完整、Redis 可达、JMAP session、Telegram `getMe`）留在后端的 `/ready` 上，`/ready` 本身被透传。
+
+## 8. 回调注册
+
+SPA 的回调 URL 只注册**一个** origin（`C-LB-SINGLE-REG-URL`）。只填 origin，不带路径：
+
+- 启用网关：填 Worker URL，例如 `https://lb.example`。
+- 不启用网关：填后端 origin，例如 `https://a.example`。
+
+你注册的是哪个 origin，`/webhook/tg` 与 `/push/jmap` 就落在哪。三个注册接口都在白名单内、都会经过网关透传，所以两种前门都能注册。注册是幂等的，且注册新地址会注销旧订阅——换前门就靠这一步。
+
+## 9. 配置
+
+- 默认值写在 `wrangler.toml` 的 `[vars]` 里，这是一个**刻意的明文例外**：当前取值只是公开可达的 https origin，不是凭据。一旦出现内网地址、带内嵌凭据的 URL、或不想公开的主机名，立刻改用 `npx wrangler secret put BACKEND_ORIGINS_JSON` 并删掉 `[vars]` 里那一行。git 历史不可逆，删掉并不等于没进过库。
+- `BACKEND_ORIGINS_JSON` 是**纯字符串数组**的 JSON。`{"url": "..."}` 这类对象形式会被拒绝：`parseBackendOrigins` 抛异常，而配置是**每个请求**重新解析的，所以表现是**每个请求都 503**，而不是启动即失败。body 为 `misconfigured backends`；空列表同样走这个异常路径，在转发任何请求之前就被拦下。
+- 每一项必须是 https **origin**：不允许 http、不允许 path、不允许 query、不允许 fragment、不允许内嵌凭据（`C-HTTPS-INBOUND`）。
+- `wrangler.toml` 同时固定 `name = "messageweave-lb"`、`main = "src/index.js"`、`compatibility_date = "2025-01-01"` 与 `compatibility_flags = ["nodejs_compat_v2"]`。`nodejs_compat_v2` 的作用是让测试文件能 import `node:test` 与 `node:assert/strict`；运行时代码不引入任何 node 模块。
+- `wrangler.toml` 的注释必须保持单行 `#` 注释。TOML 没有块注释，用 JSDoc 的 `/** */` 块会让 wrangler 直接解析不了整个配置文件。
+
+## 10. 本地与 CI 验证
+
+```bash
+cd cloudflare-worker
+
+npm test       # 四个文件共 38 条测试，全部离线
+npm run check  # 对源码与测试跑 node --check，再 wrangler deploy --dry-run
+```
+
+`npm test` 即 `node --test`，会自动收集 `test/*.test.js`：`test/index.test.js` 15、`test/lb.test.js` 12、`test/backends.test.js` 6、`test/health.test.js` 5。跑测试不需要安装依赖——Worker 没有运行时依赖，测试文件只引入 `node:test` 与 `node:assert/strict`。
+
+两个坑：
+
+- `node --test test/`（传目录）在某些 Node 版本上会跑完**零条**测试然后退出 0。必须传文件 glob。
+- 如果 CI 默认安装步骤是 `bun install`，它会忽略 npm lockfile：自行重新解析，可能把 wrangler 跨大版本移动。需要锁住 wrangler 时，在测试步骤前显式加一步 `npm ci`。
+
+## 11. 部署
+
+```bash
+cd cloudflare-worker
+npm install --no-audit --no-fund
+npm run deploy
+curl https://<your-worker>.workers.dev/healthz-worker
+```
+
+`npm run check` 内含 `wrangler deploy --dry-run --outdir=.build-check`，会在发布前把四个源文件打包并报告产物体积。网关由 push 触发部署，所以对 `/healthz-worker` 发一次 `curl` 并对比其 `version` 就是验收手段。改 LB 逻辑的提交要同时 bump `LB_VERSION`，这样才能判断线上是哪一次构建在应答。
+
+两起值得记住的生产事故：
+
+- **2026-09-30**：某次构建把 `x-lb-backend` 写进了代理响应。跨域且不带 `access-control-allow-*` 的响应 header guard 是 immutable，`headers.set` 抛异常，外层 catch 于是把一个健康的后端记成不可用并耗尽重试——网关返回 `503`，而 `GET /` 实际返回的是 `200`。`/healthz-worker` 不走那段代码，这正是事故被掩盖的原因。已改为把 header 写入做成尽力而为。
+- **对象形式的 origin 列表在解析期静默失败。** `parseBackendOrigins` 抛异常后每个请求都是 `503 misconfigured backends`。`weight` 之类的 per-origin 调参不要写进列表，没有任何地方读它们。
+
+## 12. 设计不变量
+
+- `SAF-LB-PASSTHRU` — 透传路径不改写认证、header 或 body
+- `C-HTTPS-INBOUND` — origin 仅允许 https，拒绝内嵌凭据与路径，HTTP 走 308
+- `C-LB-SINGLE-REG-URL` — 只注册一个回调 origin，未知路径 404
+- `C-LB-SHARED-SECRETS` — 所有后端携带同一组业务凭据
+- `MOD-HEALTH-AGG` — 由网关持有的带 TTL 健康聚合探测
+- `C-NO-DB`、`C-REDIS-ONLY-STATE` — 网关不访问数据库与 Redis
+- `C-NO-LONG-CONN` — 仅请求-响应
+- `ARCH-READY-BASELINE` — 端到端就绪判定留在后端的 `/ready`
+- `SAF-LOG-PURITY` — 仅 method、path、origin、失败类别
+- `ARCH-LB-WORKER` — 网关是唯一边缘组件
+- `NFR-HA-MULTI-INSTANCE` — 多 origin 故障转移即 HA 的实现方式
+
+## References
+
+- `docs/deployment.md §10` — 网关部署、配置与上线
+- `docs/reference.md §4` — 网关与后端的路由矩阵
+- `docs/reference.md §9.2` — 后端配置与 secret
+- `docs/reference.md §9.4` — 健康与发布检查
+- `docs/design.md §11.3` — HA 与多实例设计
+- `docs/charter.md §3`、`docs/charter.md §5`、`docs/charter.md §8` — 安全基线、禁令、稳定 ID 注册表
diff --git a/docs/charter.md b/docs/charter.md
index fec430c..baa8162 100644
--- a/docs/charter.md
+++ b/docs/charter.md
@@ -178,7 +178,7 @@ Answer only one question per document; **Tables, lists, or values ​​may not
 | `docs/retired.md` | Records and alternative links to abandoned or renamed plans | Historical decisions |
 | `docs/charter.md` | This document: project constraints, technology selection, implementation stage, security invariants, stable ID registry | Project constraints |
 | `web/` (no documentation, 4 files) | Manage SPA sources: static configuration pages and front-end logic, covered by `web/config.test.mjs` | Front-end behavior (authoritative facts documented in `docs/design.md` and `docs/reference.md`) |
-| `cloudflare-worker/README.md` | Configuration and semantics of the gateway itself | Gateway |
+| `cloudflare-worker/README.md` / `cloudflare-worker/README.zh-CN.md` | Configuration and semantics of the gateway itself | Gateway |
 
 **Cross-document citation rules**:
 
diff --git a/docs/charter.zh-CN.md b/docs/charter.zh-CN.md
index 0e064af..e30110a 100644
--- a/docs/charter.zh-CN.md
+++ b/docs/charter.zh-CN.md
@@ -178,7 +178,7 @@ Stalwart 与 Telegram 的业务凭据已在真机联调通过——出站、查
 | `docs/retired.md` | 已废弃或已改名方案的记录与替代指向 | 历史决策 |
 | `docs/charter.md` | 本文件：项目约束、技术选型、实现阶段、安全不变量、稳定 ID 注册表 | 项目约束 |
 | `web/`（无文档，4 个文件） | 管理 SPA 源：静态配置页与前端逻辑，由 `web/config.test.mjs` 覆盖 | 前端行为（权威事实记在 `docs/design.md` 与 `docs/reference.md`） |
-| `cloudflare-worker/README.md` | 网关自身的配置与语义 | 网关 |
+| `cloudflare-worker/README.md` / `cloudflare-worker/README.zh-CN.md` | 网关自身的配置与语义 | 网关 |
 
 **跨文档引用规则**：
 
diff --git a/scripts/docs_check/audit_anchor_semantics.py b/scripts/docs_check/audit_anchor_semantics.py
index ad1ee10..4e9c4d3 100755
--- a/scripts/docs_check/audit_anchor_semantics.py
+++ b/scripts/docs_check/audit_anchor_semantics.py
@@ -49,7 +49,8 @@ DOCS = ['AGENTS.md', 'README.md', 'README.zh-CN.md', 'docs/design.md',
         'docs/design.zh-CN.md', 'docs/deployment.md', 'docs/deployment.zh-CN.md',
         'docs/reference.md', 'docs/reference.zh-CN.md', 'docs/retired.md',
         'docs/retired.zh-CN.md', 'docs/opengaps.md', 'docs/opengaps.zh-CN.md',
-        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md']
+        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md',
+        'cloudflare-worker/README.zh-CN.md']
 
 FILE = r'((?:[A-Za-z0-9_.-]+/)?[A-Za-z0-9_-]+)'
 EXT = r'\.(rs|js):(\d+)'
diff --git a/scripts/docs_check/audit_anchors.py b/scripts/docs_check/audit_anchors.py
index 9db1946..9bb566c 100755
--- a/scripts/docs_check/audit_anchors.py
+++ b/scripts/docs_check/audit_anchors.py
@@ -45,7 +45,8 @@ DOCS = ['AGENTS.md', 'README.md', 'README.zh-CN.md', 'docs/design.md',
         'docs/design.zh-CN.md', 'docs/deployment.md', 'docs/deployment.zh-CN.md',
         'docs/reference.md', 'docs/reference.zh-CN.md', 'docs/retired.md',
         'docs/retired.zh-CN.md', 'docs/opengaps.md', 'docs/opengaps.zh-CN.md',
-        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md']
+        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md',
+        'cloudflare-worker/README.zh-CN.md']
 
 # `Ident` or `Module::Ident` inside backticks, optional () after.
 IDENT = r'[A-Za-z_][A-Za-z0-9_]*(?:::[A-Za-z_][A-Za-z0-9_]*)?'
diff --git a/scripts/docs_check/check_sec_refs.py b/scripts/docs_check/check_sec_refs.py
index e212ac9..1e8b4d1 100755
--- a/scripts/docs_check/check_sec_refs.py
+++ b/scripts/docs_check/check_sec_refs.py
@@ -17,7 +17,8 @@ DOCS = ["AGENTS.md", "README.md", "README.zh-CN.md", "docs/design.md",
         "docs/design.zh-CN.md", "docs/deployment.md", "docs/deployment.zh-CN.md",
         "docs/reference.md", "docs/reference.zh-CN.md", "docs/retired.md",
         "docs/retired.zh-CN.md", "docs/opengaps.md", "docs/opengaps.zh-CN.md",
-        "docs/charter.md", "docs/charter.zh-CN.md", "cloudflare-worker/README.md"]
+        "docs/charter.md", "docs/charter.zh-CN.md", "cloudflare-worker/README.md",
+        "cloudflare-worker/README.zh-CN.md"]
 
 HEADING = re.compile(r"^(#{2,4})\s+(\d+(?:\.\d+)?\.?)\s")
 # §2.3, §5.7, §3 (bare), also `§2.3/§3.4` chains handled by finditer
@@ -42,12 +43,23 @@ def headings(path):
 
 def main():
     names = {os.path.basename(p): p for p in DOCS}
-    heads = {os.path.basename(p): headings(os.path.join(ROOT, p)) for p in DOCS}
+    # `README.md` exists both at the repo root and under `cloudflare-worker/`, so a
+    # basename-keyed map silently drops one of them. Keep every file's own heading
+    # set and let the first occurrence win on a basename collision.
+    own_heads = {p: headings(os.path.join(ROOT, p)) for p in DOCS}
+    heads = {}
+    for p in DOCS:
+        heads.setdefault(os.path.basename(p), own_heads[p])
     errors = []
     checked = 0
 
     for rel in DOCS:
         base = os.path.basename(rel)
+        # A basename held by more than one file (`README.md` lives both at the
+        # repo root and under `cloudflare-worker/`) must resolve against the
+        # document being scanned when it names that document itself.
+        heading_set = (lambda t: own_heads[rel] if t == base
+                       else heads.get(t, set()))
         full = os.path.join(ROOT, rel)
         with open(full, encoding="utf-8") as fh:
             for lineno, line in enumerate(fh, 1):
@@ -69,7 +81,7 @@ def main():
                     target = m.group(1)
                     override_pos = m.end()
                     checked += 1
-                    if m.group(2) not in heads.get(target, set()):
+                    if m.group(2) not in heading_set(target):
                         errors.append(
                             f"{rel}:{lineno}: §{m.group(2)} does not exist "
                             f"in {target}")
@@ -93,7 +105,7 @@ def main():
                             re.search(r"([A-Za-z0-9_.-]+\.md)[`\s]*$",
                                       prefix).group(1))
                     checked += 1
-                    if num not in heads.get(target, set()):
+                    if num not in heading_set(target):
                         errors.append(
                             f"{rel}:{lineno}: §{num} does not exist in {target}")
 
diff --git a/scripts/docs_check/check_tables.py b/scripts/docs_check/check_tables.py
index f9a8b49..d4a1fb3 100755
--- a/scripts/docs_check/check_tables.py
+++ b/scripts/docs_check/check_tables.py
@@ -6,7 +6,8 @@ DOCS = ['AGENTS.md', 'README.md', 'README.zh-CN.md', 'docs/design.md',
         'docs/design.zh-CN.md', 'docs/deployment.md', 'docs/deployment.zh-CN.md',
         'docs/reference.md', 'docs/reference.zh-CN.md', 'docs/retired.md',
         'docs/retired.zh-CN.md', 'docs/opengaps.md', 'docs/opengaps.zh-CN.md',
-        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md']
+        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md',
+        'cloudflare-worker/README.zh-CN.md']
 
 CODE = re.compile(r'`[^`\n]*`')
 SEP = re.compile(r'^\s*\|?\s*:?-{3,}:?\s*(\|\s*:?-{3,}:?\s*)+\|?\s*$')
diff --git a/scripts/docs_check/validate_docs.py b/scripts/docs_check/validate_docs.py
index 825b2ec..5f87ed8 100755
--- a/scripts/docs_check/validate_docs.py
+++ b/scripts/docs_check/validate_docs.py
@@ -5,7 +5,8 @@ DOCS = ['AGENTS.md', 'README.md', 'README.zh-CN.md', 'docs/design.md',
         'docs/design.zh-CN.md', 'docs/deployment.md', 'docs/deployment.zh-CN.md',
         'docs/reference.md', 'docs/reference.zh-CN.md', 'docs/retired.md',
         'docs/retired.zh-CN.md', 'docs/opengaps.md', 'docs/opengaps.zh-CN.md',
-        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md']
+        'docs/charter.md', 'docs/charter.zh-CN.md', 'cloudflare-worker/README.md',
+        'cloudflare-worker/README.zh-CN.md']
 errors = []
 
 def slug(t):