feat(portal-shell): add graphql-codegen configuration

M1 Task 2: 配置 graphql-codegen 与 federation schema 预处理

- codegen.yml: schema 从 combined-schema.graphql 读取（federation 已剥离）

- scripts/normalize-schema.ts: 把 7 个子图的 extend type Query 合并为 type Query

- package.json: 新增 codegen/codegen:watch scripts + 4 个 codegen deps + tsx

- .gitignore: 忽略 src/lib/api/__generated__/

- documents 配置暂注释，Task 3 创建 operations 文件后启用

apps/portal-shell/codegen.yml

@@ -0,0 +1,30 @@
+# graphql-codegen configuration
+#
+# Schema source: combined-schema.graphql (generated by scripts/normalize-schema.ts
+# from services subgraph SDL files, with federation `extend type Query` normalized).
+#
+# Subgraph list (7 with GraphQL): iam / config-service / core-edu / content /
+# msg / data-ana / ai (classes has no GraphQL subgraph yet).
+#
+# Outputs:
+# - __generated__/types.ts: all GraphQL schema types (always generated)
+# - __generated__/operations.ts: TypedDocumentNode (enabled after Task 3 creates
+#   operations/*.graphql.ts files)
+#
+# Related: spec section 2.4
+
+schema: src/lib/api/__generated__/combined-schema.graphql
+
+# documents: src/lib/api/operations/**/*.graphql.ts
+# (re-enabled in Task 3 after operations files exist)
+
+generates:
+  src/lib/api/__generated__/types.ts:
+    plugins:
+      - typescript
+
+config:
+  preResolveTypes: true
+  skipTypename: true
+  exportTypeKeyOnly: true
+  useTypeImports: true