Make the offline RAG chain observable without widening credential access

Expose the verified synthetic retrieval path through a typed React client and a non-root Nginx edge while keeping database credentials and data-network reachability out of the browser tier. A fixed-origin gateway preserves request boundaries and now closes upstream streams even when downstream disconnects before body iteration. The deployment ADR and runbooks record the four-network topology and its accepted Web edge-egress risk.

Constraint: The previously exposed Bailian key must be revoked and no live provider credential may enter Git, images, logs, or the browser.
Rejected: Connect Web directly to the data network | expands lateral reach to PostgreSQL.
Rejected: Publish the database-aware API on the edge network | gives a credential-bearing process a public default route.
Rejected: Buffer streaming responses in either proxy | prevents incremental chat delivery in the future.
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Do not mark Stage 1 or Stage 2 complete until the rotated-key live smoke and remaining stage gates pass.
Tested: make verify; 65 backend tests; 14 frontend tests; Docker image build; container health and isolation probes; real HTTP demo/status/search/docs/OpenAPI checks.
Not-tested: Live Bailian models, real document ingestion, business chat SSE generation, and final browser screenshot automation because the browser skill runtime was unavailable.

docs/05-stage1-runbook.md

@@ -21,7 +21,7 @@ bash scripts/init-local-secrets.sh
 离线模式使用确定性的 1024 维 feature-hash 向量和词法重排器，只验证数据治理、批处理、迁移、向量写入、权限过滤、检索、重排和幂等性，不把它当成真实模型质量。
 
 ```bash
-docker compose up -d --build gateway
+docker compose up -d --build web
 docker compose --profile tools run --rm seed-demo-offline
 docker compose --profile tools run --rm seed-demo-offline
 ```
@@ -46,7 +46,7 @@ Seed 的实际流程是：
 
 ### 2.1 查看后端运行效果
 
-内部 API 只连接 `internal` data 网络，只挂载 app 数据库 Secret，不连接外网，也不挂载百炼 Key。无 Secret、无数据库凭证的 gateway 同时连接 ingress 与 data 网络，并且仅发布到本机回环地址 `127.0.0.1:8000`。两个容器都以数值非 root 用户运行，根文件系统只读，并移除 Linux capabilities。
+内部 API 只连接 `internal` data 网络，只挂载 app 数据库 Secret，不连接外网，也不挂载百炼 Key。无 Secret、无数据库凭证的 gateway 连接 internal ingress/data；React/Nginx Web 连接 edge/ingress，并且是唯一发布到本机回环地址 `127.0.0.1:8000` 的容器。三个运行容器均使用非 root 用户、只读根文件系统并移除 Linux capabilities。
 
 ```bash
 curl http://127.0.0.1:8000/health/live