refactor(data): 收口关系表运行时数据源

- 移除已迁移业务 AppData 运行时 fallback，改走领域 API 和关系表快读
- 补齐需求产品负责人、版本计划任务 JSON 和成员 username 回填迁移
- 统一治理字典入口，并补充 AI provider、数据源契约和领域服务测试

Co-Authored-By: Codex GPT-5 <codex@openai.com>

apps/web/lib/api.test.ts

@@ -112,3 +112,20 @@ test('API availability probe retries after a transient failure', async () => {
     globalThis.fetch = originalFetch;
   }
 });
+
+test('raw API requests map abort errors to a readable timeout message', async () => {
+  const originalFetch = globalThis.fetch;
+
+  globalThis.fetch = (async () => {
+    throw new Error('signal is aborted without reason');
+  }) as typeof fetch;
+
+  try {
+    await assert.rejects(
+      () => api.postRaw('/ai/decompose', {}, 1),
+      /请求超时/,
+    );
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});