refactor(framework): 移除 resolveBootstrap 下游兜底，立第二准则

- CLAUDE.md 新增「第二准则：数据源权威、唯一，下游不兜底」
- bootstrap 删除 fallbackServers 选项与 ?? DEFAULT_GAMESERVER 猜默认
- 无 server/gameserver、远程失败、解析不出地址 → 一律抛 ConfigFetchError 显式暴露
- 同步 guide + 两篇 spec（删 fallback/降级措辞）

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cocoscreator_projects/framework-tests/config/bootstrap.test.ts

@@ -47,18 +47,21 @@ test('debug + 原生模式：identity 来自 window.settings', async () => {
   assert.equal(r.identity.marketid, 3);
 });
 
-test('debug + 远程失败 + 有 fallbackServers → 降级使用', async () => {
-  const r = await resolveBootstrap({ mode: 'debug', win: {}, search: '', fetcher: throwingFetcher, isNative: false, fallbackServers: ['ws://fb:1'] });
-  assert.deepEqual(r.servers, ['ws://fb:1']);
-});
-
-test('debug + 远程失败 + 无 fallback → 抛 ConfigFetchError', async () => {
+test('远程抓取失败 → 抛 ConfigFetchError（不兜底）', async () => {
   await assert.rejects(
     resolveBootstrap({ mode: 'debug', win: {}, search: '', fetcher: throwingFetcher, isNative: false }),
     /远程配置抓取失败/,
   );
 });
 
+test('远程配置未给出可用服务器地址 → 抛错（不兜底）', async () => {
+  const emptyFetcher: ConfigFetcher = { fetch: async () => ({ data: {} }) };
+  await assert.rejects(
+    resolveBootstrap({ mode: 'debug', win: {}, search: '', fetcher: emptyFetcher, isNative: false }),
+    /未给出可用服务器/,
+  );
+});
+
 test('debug 结果含 mode/isDebugger', async () => {
   const fetcher = fetcherReturning(REMOTE);
   const r = await resolveBootstrap({ mode: 'debug', win: {}, search: '', fetcher, isNative: false });