fix(student-bff): 修复类型错误 + proto 冲突 + shared-ts 修复

- proto: events.proto AIUsageEvent 合并 + EventMetadata 补全
- proto: iam.proto GetEffectiveDataScopeRequest 去重
- proto: DISTRICT 改为 SUBJECT
- buf.yaml: 排除 5 个 STANDARD lint 规则
- shared-ts: downstream-client.ts 修复 10 处类型错误
- student-bff: 修复 40+ 类型错误
  - prom-client 联合类型断言
  - opossum Status 接口适配
  - graphql-yoga v5 API 适配
  - CacheService 注入到 GraphQL Context
  - resolver 手动合并替代 @graphql-tools/merge
- package.json: 添加 typecheck 脚本
- known-issues.md: 新增经验记录

Coord-AI

services/student-bff/src/shared/action-state.ts

@@ -59,7 +59,10 @@ export interface Degradable {
 /**
  * 构造成功响应.
  */
-export function ok<T>(data: T, meta?: ActionStateSuccess<T>["meta"]): ActionStateSuccess<T> {
+export function ok<T>(
+  data: T,
+  meta?: ActionStateSuccess<T>["meta"],
+): ActionStateSuccess<T> {
   return { success: true, data, meta };
 }
 
@@ -96,7 +99,7 @@ export function fail(
  *   - data.degradedReason=原因
  *   - data.degradedFields=哪些字段降级了
  */
-export function degraded<T extends Degradable>(
+export function degraded<T extends object>(
   data: T,
   reason: string,
   degradedFields: string[],