refactor(core): migrate to Bun and converge acquisition policies and Agent boundaries

apps/server/test/search/search.test.ts

@@ -153,7 +153,7 @@ describe.skipIf(!up)("全局搜索", () => {
       capabilities: createCapabilityRegistry({ logger }),
     } as ServerContext;
     // 挂起的站点:请求一直不返回,直到被中止(单站超时)
-    const fetchImpl: typeof fetch = (input, init) => {
+    const fetchImpl: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response> = (input, init) => {
       const url = new URL(input instanceof Request ? input.url : String(input));
       if (url.hostname !== SLOW_HOST) return fetch(input, init);
       slowCalls++;