fix: 修复集成测试中发现的全部 bug — 15 服务端到端验证通过

修复涵盖 6 大类问题：

1. api-gateway
   - 路径前缀剥离 /api 而非 /api/v1，保留下游 /v1/ controller 前缀
   - JWKS URL 默认值修复
   - publicPaths 白名单对齐 /v1/iam/*

2. iam
   - iam.module.ts exports 补充 PermissionCacheService 和 IamRepository
   - main.ts resolveProtoPath() 多路径探测 proto 文件

3. core-edu
   - app.module.ts AuthMiddleware 全局注册

4. BFF 层 GraphQL 端点（teacher-bff / parent-bff / student-bff）
   - teacher-bff: mock dataScope OWN→SELF 对齐 GraphQL enum；WHATWG Request header .get() 提取
   - parent-bff: handleNodeRequestAndResponse 不存在 → 直接 yoga(req,res)；WHATWG Request header .get() 提取
   - student-bff: auth.resolver 移除 ActionState 信封返回扁平对象；WHATWG Request header .get() 提取

5. ai
   - Kafka 事务降级 + 10s 超时
   - gRPC 拦截器降级
   - dev mode 禁用事务模式

6. 前端 + 共享包
   - teacher-portal: MF 插件条件实例化 + transpilePackages + extensionAlias
   - ui-components: error-boundary.tsx 添加 use client
   - ui-tokens: tailwind-theme.css 移除 @layer base
   - shared-ts: 导出从源码改为 dist 编译产物；OutboxModule global:true

7. infra
   - .gitignore 补充 keys/ *.pem *.key secrets/ 排除规则
   - infra/init-sql/02-all-services-schema.sql 36 张表 DDL

验证结果：
- TS typecheck: 19 个 workspace 项目全部通过
- Go vet + Ruff: 通过
- 15 服务全部启动成功
- 3 个 BFF GraphQL 端点 + 4 个前端页面全部 200
- Gateway → iam → core-edu 端到端链路验证通过

AI identity: trae-main（集成测试修复会话）

packages/shared-ts/contracts/graphql/student-bff.schema.graphql

@@ -452,6 +452,12 @@ type WeakPoint {
   lastAssessedAt: DateTime
 }
 
+type LearningTrendSummary {
+  studentId: ID!
+  subjectId: ID
+  points: [TrendPoint!]!
+}
+
 type LearningTrend {
   studentId: ID!
   subjectId: ID
@@ -567,6 +573,12 @@ type AIChatPayload implements Degradable {
   degradedFields: [String!]
 }
 
+input AIChatInput {
+  messages: [AIChatMessageInput!]!
+  model: String = "gpt-4o-mini"
+  context: AIChatContextInput
+}
+
 # ============================================================================
 # Mutation 结果
 # ============================================================================
@@ -723,6 +735,11 @@ type Query {
   # @permission: NOTIFICATION_READ
   # @dataScope: OWN
   myNotificationUnreadCount: UnreadCountPayload!
+
+  """AI 答疑 (同步, ai.Chat). 实际为写操作但 schema 设计为 Query 便于前端 GET 缓存"""
+  # @permission: STUDENT_AI_CHAT
+  # @dataScope: OWN
+  aiChat(input: AIChatInput!): AIChatPayload!
 }
 
 # ============================================================================