feat(api-gateway): retire teacher/student/parent-bff, route GraphQL to apollo-router

v2.1 M9+M10: BFF layer and old portals retired.

- api-gateway: remove TeacherBffURL/StudentBffURL/ParentBffURL config

- api-gateway: add ApolloRouterURL config and /api/graphql route

- api-gateway: /api/admin/graphql now proxies to apollo-router

- api-gateway: health checks now ping apollo-router instead of BFF

- deploy.yml: replace teacher-bff service block with apollo-router

- deploy.yml: add config-service service block (M3 dependency)

- deploy.yml: remove teacher-portal and admin-portal service blocks

- source code in services/{teacher,student,parent}-bff/ and apps/*-portal/ retained for rollback

services/api-gateway/internal/health/health.go

@@ -29,20 +29,20 @@ type downstreamCheck struct {
 // GET /readyz：并行 ping 下游服务 /healthz，超时 2s。
 //
 // 软失败规则（president-final-rulings.md §3.3）：
-//   - 必需依赖（iam / teacher-bff，P2 已就绪）失败 → 503
-//   - 可选依赖（P3-P5 未就绪服务）失败 → 200 + degraded 列表
+//   - 必需依赖（iam / apollo-router）失败 → 503
+//   - 可选依赖（core-edu / content / msg / ai / data-ana）失败 → 200 + degraded 列表
 //   - 全部可达 → 200 {"status":"ok"}
+//
+// v2.1 M9：teacher-bff / student-bff / parent-bff 已下线，由 apollo-router 替代。
 func Readyz(cfg *config.Config) gin.HandlerFunc {
 	checks := []downstreamCheck{
 		{name: "iam", url: cfg.IamServiceURL + "/healthz", required: true},
-		{name: "teacher-bff", url: cfg.TeacherBffURL + "/healthz", required: true},
+		{name: "apollo-router", url: cfg.ApolloRouterURL + "/healthz", required: true},
 		{name: "core-edu", url: cfg.CoreEduServiceURL + "/healthz", required: false},
 		{name: "content", url: cfg.ContentServiceURL + "/healthz", required: false},
 		{name: "msg", url: cfg.MsgServiceURL + "/healthz", required: false},
 		{name: "ai", url: cfg.AiServiceURL + "/healthz", required: false},
 		{name: "data-ana", url: cfg.DataAnaServiceURL + "/healthz", required: false},
-		{name: "student-bff", url: cfg.StudentBffURL + "/healthz", required: false},
-		{name: "parent-bff", url: cfg.ParentBffURL + "/healthz", required: false},
 	}
 
 	client := &http.Client{Timeout: 2 * time.Second}