New operation becames override after dashboard restart in use dynamic datasource like nacos

## Issue Description

Type: *bug report*

### Describe what happened (or what feature you want)

New operation becames override after dashboard restart in use dynamic datasource like nacos.

### Describe what you expected to happen

Add new rule, not override.

### How to reproduce it (as minimally and precisely as possible)

1. use nacos for datasource
2. add some flow rules
3. restart dashboard
4. add new rule

### Tell us your environment

sentinel-1.8.2

nacos-1.2.1

### Anything else we need to know?

After dashboard restart ids reset to 0, after query all rules because old rules has id, ids remain 0.



Start by reproducing the issue with Sentinel 1.8.2 and Nacos 1.2.1 using the listed four-step flow, then inspect the dashboard's dynamic datasource integration and rule ID handling after restart. Done means adding a new flow rule preserves the existing rules instead of overriding one.

Written by the indexing model from the issue text.