Is your feature request related to a problem?

Currently, the Clash / Mihomo Global Routing Rules feature in 3x-ui only preserves the rules section and removes any rule-providers configuration.

For example, when the following configuration is entered:

rules:

• RULE-SET,google,PROXY

rule-providers:
google:
type: http
behavior: domain
url: https://cdn.jsdelivr.net/gh/Loyalsoldier/clash-rules@release/google.txt
path: ./ruleset/google.yaml
interval: 86400

The generated subscription only contains:

rules:

• RULE-SET,google,PROXY

The entire rule-providers section is removed.

As a result, Clash/Mihomo clients may report errors such as:

rule provider google not found

and the corresponding RULE-SET entries cannot function correctly.

Describe the solution you'd like

I would like 3x-ui to support custom Clash/Mihomo Rule Providers.

Possible implementation options:

Alternatives you've considered

No response

Concrete use case

No response

Mockups, screenshots, or examples

No response

Which parts of the panel would this affect?

Subscription (share links / Clash / JSON)

Are you willing to help?

• I'd like to implement this feature myself and open a PR.
• I can help test once a PR is open.

Before submitting

• I searched existing issues and this feature has not been requested.
• This feature request is written in English.