proposal: Adding the ability to manage multiple servers through the Web UI

[yohamta]

See also #309

Example:

host: serverA
port: 80
servers:
  - host: serverB
    port: 80
  - host: serverB
    port: 80

• [ ] Add a servers field to admin config definition
• [ ] Update admin Web UI so that user can switch the server

[fishnux]

What's this about?

[yohamta]

With this feature, users will be able to manage multiple servers via the Web UI. Even if there are multiple Dagu servers, they can all be accessed through a single URL. We believe this will enhance the user experience and make server management more efficient. However, we understand that this might not be the best solution, and we welcome any feedback or suggestions on how to improve this feature. Let's work together to enhance the functionality of our OSS and provide a better experience for our users.