fix: harden AI analysis and seed defaults

app/api/ai/ai-routes.test.ts

@@ -140,7 +140,7 @@ const analysis: ElderAiAnalysisHistoryItem = {
     modelSummary: {
       provider: "openai-compatible",
       chatModel: "gpt-test",
-      embeddingModel: "embedding-test",
+      knowledgeRetrieval: "keyword",
     },
   },
 };
@@ -293,14 +293,14 @@ describe("AI API routes", () => {
   });
 
   it("propagates knowledge service failures with the service status", async () => {
-    vi.mocked(createKnowledgeEntry).mockResolvedValue({ success: false, reason: "知识库向量生成失败", status: 500 });
+    vi.mocked(createKnowledgeEntry).mockResolvedValue({ success: false, reason: "知识库创建失败", status: 500 });
 
     const { POST } = await import("./knowledge/route");
     const response = await POST(jsonRequest({ ...knowledgeInput }));
     const body = await readJson(response);
 
     expect(response.status).toBe(500);
-    expect(body).toEqual({ success: false, reason: "知识库向量生成失败" });
+    expect(body).toEqual({ success: false, reason: "知识库创建失败" });
     expect(recordAuditLog).not.toHaveBeenCalled();
   });