fix: support hours, minutes, and seconds to the filter field.

[endxxxx]

Description

When retrieving preference memories, the filter field supports queries in hours, minutes, and seconds.

Related Issue (Required): Fixes #1075

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Test Script Or Test Steps (please provide)

def get_memory():
    data = {
      "user_id": user_id,
      "filter": {
          "and": [
              {
                  "create_time": {
                      "gte": "2026-01-01 20:01:39" # add hours, minutes, and seconds
                  }  
              }
          ] 
      },
      "include_preference": True,
      "include_tool_memory": True,
      "page": 1,
      "page_size": 10
    }
    headers = {
        "Content-Type": "application/json",
        "Authorization": f"Token {os.environ['MEMOS_API_KEY']}"
    }
    url = f"{os.environ['MEMOS_BASE_URL']}/get/memory"
    
    res = requests.post(url=url, headers=headers, data=json.dumps(data))

    return res.json()

Checklist

• I have performed a self-review of my own code | 我已自行检查了自己的代码
• I have commented my code in hard-to-understand areas | 我已在难以理解的地方对代码进行了注释
• I have added tests that prove my fix is effective or that my feature works | 我已添加测试以证明我的修复有效或功能正常
• I have created related documentation issue/PR in MemOS-Docs (if applicable) | 我已在 MemOS-Docs 中创建了相关的文档 issue/PR（如果适用）
• I have linked the issue to this PR (if applicable) | 我已将 issue 链接到此 PR（如果适用）
• I have mentioned the person who will review this PR | 我已提及将审查此 PR 的人

Reviewer Checklist

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Made sure Checks passed
• Tests have been provided