feat(ticket): 列表支持按标题/正文搜索

手机端工单列表要能像任务、知识一样搜。与知识列表同一套 ilike 匹配，标题记不清时正文关键词也能命中；补测试覆盖标题命中、正文命中、无结果三种情况。

backend/tests/test_tickets.py

@@ -315,6 +315,64 @@ async def test_ticket_list_scopes(client: AsyncClient) -> None:
     assert empty["tickets"] == []
 
 
+@pytest.mark.asyncio
+async def test_ticket_list_search(client: AsyncClient) -> None:
+    """手机端工单列表的搜索框：标题和正文都能命中，不相关的不出现。"""
+    owner = await login(client)
+    ws = await create_workspace(client, owner, "工单搜索")
+    helper = await _member(client, owner, ws)
+    task = await _task(client, owner, ws["id"], "支付回调重复")
+    unwrap(
+        await client.patch(
+            f"{V1}/workspaces/{ws['id']}/items/{task['id']}",
+            json={"body_md": "网关在 23:00 之后重复回调了三次", "version": task["version"]},
+            headers=owner["headers"],
+        )
+    )
+    unwrap(
+        await client.post(
+            f"{V1}/workspaces/{ws['id']}/items/{task['id']}/promote",
+            json={"assignee_id": helper["user_id"]},
+            headers=owner["headers"],
+        )
+    )
+    other = await _task(client, owner, ws["id"], "登录页白屏")
+    unwrap(
+        await client.post(
+            f"{V1}/workspaces/{ws['id']}/items/{other['id']}/promote",
+            json={"assignee_id": helper["user_id"]},
+            headers=owner["headers"],
+        )
+    )
+
+    by_title = unwrap(
+        await client.get(
+            f"{V1}/workspaces/{ws['id']}/tickets",
+            params={"role": "all", "q": "支付"},
+            headers=helper["headers"],
+        )
+    )
+    assert [t["title"] for t in by_title["tickets"]] == ["支付回调重复"]
+
+    by_body = unwrap(
+        await client.get(
+            f"{V1}/workspaces/{ws['id']}/tickets",
+            params={"role": "all", "q": "网关"},
+            headers=helper["headers"],
+        )
+    )
+    assert [t["title"] for t in by_body["tickets"]] == ["支付回调重复"]
+
+    miss = unwrap(
+        await client.get(
+            f"{V1}/workspaces/{ws['id']}/tickets",
+            params={"role": "all", "q": "不存在的关键词"},
+            headers=helper["headers"],
+        )
+    )
+    assert miss["tickets"] == []
+
+
 @pytest.mark.asyncio
 async def test_cross_tenant_ticket_invisible(client: AsyncClient) -> None:
     alice = await login(client)