fix: 消除并发测试中的 tool 导出竞争和 SQLite 目录碰撞

tests/server/mocks/ai.ts

@@ -0,0 +1,36 @@
+import { mock } from "bun:test";
+
+void mock.module("ai", () => ({
+  createAgentUIStreamResponse: (opts: {
+    agent: unknown;
+    messages: unknown[];
+    onFinish:
+      | ((event: { finishReason?: string; responseMessage: { parts?: Array<{ text: string; type: string }> } }) => void)
+      | undefined;
+  }) => {
+    if (opts.onFinish) {
+      opts.onFinish({
+        responseMessage: {
+          parts: [{ text: "test reply from AI", type: "text" }],
+        },
+      });
+    }
+    return Promise.resolve(
+      new Response(
+        'data: {"type":"start-step"}\n\ndata: {"type":"text-start","id":"txt-1"}\n\ndata: {"type":"text-delta","id":"txt-1","delta":"test reply from AI"}\n\ndata: {"type":"text-end","id":"txt-1"}\n\ndata: {"type":"finish-step"}\n\ndata: {"type":"finish"}\n\n',
+        {
+          headers: { "Content-Type": "text/event-stream" },
+        },
+      ),
+    );
+  },
+  createProviderRegistry: () => ({
+    languageModel: () => ({}),
+  }),
+  generateText: () => Promise.resolve({ text: "AI\u603B\u7ED3\u6807\u9898", usage: {} }),
+  stepCountIs: () => () => true,
+  tool: () => ({ execute: async () => await Promise.resolve({}) }),
+  ToolLoopAgent: function M() {
+    // no-op: createAgentUIStreamResponse handles streaming
+  },
+}));