[orchestrator]: Separate Russula constructors for Coordinator and Worker

### Problem:
Currently the Coordinator and Worker both take a list of peers to connect to. While this works, the Worker should only ever be connecting to a single Coordinator and doent need to take a list.

### Solution
Create different builder/endpoint for Coordinator/Workers to capture different usage patterns.

Locate the orchestrator entry points and current Coordinator and Worker constructors, then trace their builder/endpoint usages. Separate the construction paths so a Coordinator can retain peer-list behavior while a Worker accepts only one Coordinator, and verify all existing call sites still build and behave correctly.

Written by the indexing model from the issue text.