feat(server): ServerModule skeleton with shared ServerContext, worker runs engine + outbox relay (B6)

modules/{auth-settings,sources-identity,acquisition-organize,agent} placeholders listed in
SERVER_MODULES; ServerModule registers routes (under /api/v1, authenticated), tasks,
outbox routes, capabilities and background loops. bootstrap() builds ServerContext (db,
config, logger, events, engine, outbox writer, secrets placeholder, settings reader,
capability registry), fills unregistered tasks with stubs and rejects duplicate task or
outbox ownership. worker starts the OpenWorkflow worker, OutboxRelay and module start().
--role migrate also migrates the engine schema; api/worker connect without migrating.
tasks: TaskRegistry.has, migrateEngineSchema.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/runbook/dev.md

@@ -48,7 +48,9 @@ curl -N -H "Authorization: Bearer umt-dev-admin-key" "localhost:4380/api/v1/even
 
 `umt-server --role api|worker|all`(源码:`deno run ... apps/server/src/main.ts --role ...`)。`all` 下 worker 心跳会发布到进程内事件总线,SSE 可见;分进程部署时事件总线需改为 PG 投影(W2)。
 
-一次性子命令(容器入口用):`--role migrate`(迁移到最新,迁移文件已编进二进制)、`--role preflight`(启动自检:生产环境拒绝占位符密钥与 root、DB 可达、`WEB_ROOT/index.html` 存在)、`--role probe`(打本机 `/api/v1/health`,HEALTHCHECK 用)。
+启动时 `bootstrap()` 装配 `apps/server/src/modules/` 下的四个业务模块(见 apps/server/README.md),并连接任务引擎;`api` 角色也连接引擎(入队/信号/取消),`worker`/`all` 角色额外启动引擎 worker 与 OutboxRelay。数据库不可达时进程启动失败并退出。
+
+一次性子命令(容器入口用):`--role migrate`(迁移到最新,迁移文件已编进二进制;随后迁移任务引擎的 openworkflow schema)、`--role preflight`(启动自检:生产环境拒绝占位符密钥与 root、DB 可达、`WEB_ROOT/index.html` 存在)、`--role probe`(打本机 `/api/v1/health`,HEALTHCHECK 用)。
 
 设置 `WEB_ROOT` 后 API 进程在同一端口托管 web 构建产物:存在的文件直接返回,其余非 `/api` 路径回退 `index.html`。