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/config/config.go

@@ -9,6 +9,9 @@ import (
 // Config 持有 api-gateway 运行时配置。
 // P2 起 JWT 验签改 RS256（IAM 签发，Gateway 用 JWKS 公钥校验），
 // JWTSecret 仅在 DevMode 下作为 mock 密钥保留。
+//
+// v2.1 M9：teacher-bff / student-bff / parent-bff 已下线，
+// 由 apollo-router（GraphQL 联邦）替代 BFF 聚合层。
 type Config struct {
 	Port              string
 	JWKSURL           string // RS256 公钥端点（IAM GET /.well-known/jwks.json）
@@ -18,9 +21,7 @@ type Config struct {
 	CORSOrigins       string
 	ClassesServiceURL string
 	IamServiceURL     string
-	TeacherBffURL     string
-	StudentBffURL     string
-	ParentBffURL      string
+	ApolloRouterURL   string // v2.1 M9：apollo-router GraphQL 联邦入口
 	CoreEduServiceURL string
 	ContentServiceURL string
 	DataAnaServiceURL string
@@ -77,9 +78,7 @@ func Load() *Config {
 		CORSOrigins:       getEnv("CORS_ORIGINS", ""),
 		ClassesServiceURL: getEnv("CLASSES_SERVICE_URL", "http://localhost:3001"),
 		IamServiceURL:     getEnv("IAM_SERVICE_URL", "http://localhost:3002"),
-		TeacherBffURL:     getEnv("TEACHER_BFF_URL", "http://localhost:3003"),
-		StudentBffURL:     getEnv("STUDENT_BFF_URL", "http://localhost:3009"),
-		ParentBffURL:      getEnv("PARENT_BFF_URL", "http://localhost:3010"),
+		ApolloRouterURL:   getEnv("APOLLO_ROUTER_URL", "http://localhost:3000"),
 		CoreEduServiceURL: getEnv("CORE_EDU_SERVICE_URL", "http://localhost:3004"),
 		ContentServiceURL: getEnv("CONTENT_SERVICE_URL", "http://localhost:3005"),
 		DataAnaServiceURL: getEnv("DATA_ANA_SERVICE_URL", "http://localhost:3006"),