Please add support for multiple real servers serving same ip address (ie load balancing of legit traffic)

For example hosts.yml would look like this:
```
- ip: 1.1.1.1
- srv1:
secrets_addr: udp://2.2.2.1:1111
mac: 02:02:02:02:02:01
- srv2:
secrets_addr: udp://2.2.2.2:1111
mac: 02:02:02:02:02:02
- srv3:
secrets_addr: udp://2.2.2.3:1111
mac: 02:02:02:02:02:03
```
So packets would be sent to srv1-3 based on hash of src ip:port. Adding a weighted balancing might be useful too.

The issue names hosts.yml and source ip:port hashing, but no implementation files or tests. Start by locating the hosts.yml parser and packet-dispatch entry point, then clarify whether weighted balancing is required. Done should include multiple servers for one IP with deterministic distribution and coverage for the selection behavior.

Written by the indexing model from the issue text.