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/observability/metrics.ts

@@ -127,33 +127,35 @@ export function recordDownstreamCall(
   errorType?: string,
 ): void {
   const labels = { service, method, status };
-  registry
-    .getSingleMetric("student_bff_downstream_calls_total")
-    ?.inc(labels);
-  registry
-    .getSingleMetric("student_bff_downstream_duration_seconds")
-    ?.observe({ service, method }, durationMs / 1000);
+  (
+    registry.getSingleMetric("student_bff_downstream_calls_total") as
+      promClient.Counter<string> | undefined
+  )?.inc(labels);
+  (
+    registry.getSingleMetric("student_bff_downstream_duration_seconds") as
+      promClient.Histogram<string> | undefined
+  )?.observe({ service, method }, durationMs / 1000);
   if (status === "error" && errorType) {
-    registry
-      .getSingleMetric("student_bff_downstream_errors_total")
-      ?.inc({ service, method, error_type: errorType });
+    (
+      registry.getSingleMetric("student_bff_downstream_errors_total") as
+        promClient.Counter<string> | undefined
+    )?.inc({ service, method, error_type: errorType });
   }
 }
 
 /**
  * 缓存命中/未命中指标辅助器.
  */
-export function recordCacheAccess(
-  keyPattern: string,
-  hit: boolean,
-): void {
+export function recordCacheAccess(keyPattern: string, hit: boolean): void {
   if (hit) {
-    registry
-      .getSingleMetric("student_bff_cache_hits_total")
-      ?.inc({ cache_key_pattern: keyPattern });
+    (
+      registry.getSingleMetric("student_bff_cache_hits_total") as
+        promClient.Counter<string> | undefined
+    )?.inc({ cache_key_pattern: keyPattern });
   } else {
-    registry
-      .getSingleMetric("student_bff_cache_misses_total")
-      ?.inc({ cache_key_pattern: keyPattern });
+    (
+      registry.getSingleMetric("student_bff_cache_misses_total") as
+        promClient.Counter<string> | undefined
+    )?.inc({ cache_key_pattern: keyPattern });
   }
 }