Add first-class support for Hermes

### Before filing

- [x] I searched [open and closed issues](https://github.com/block/berd/issues?q=is%3Aissue) for duplicates.
- [x] I am using a recent [release](https://github.com/block/berd/releases) and this doesn't already exist.
- [x] This is one request, not several bundled together.

### Closest existing issue

https://github.com/block/berd/issues/110

### Is this new, or an improvement?

New capability — Berd can't do this at all today

### The problem, in your terms

Considering adoption is high, first-class support for Hermes would enable this to be a replacement for other tools like Codex/Hermes Desktop/etc. This would allow controlling Hermes from Berd while letting Hermes retain tooling, memory, etc. Essentially, what Buzz does but for the single player experience.

_Berd – and Buzz – are freakin' amazing. Thank you!_

### What you do today

Today I either use Buzz and have a 1:1 chat with the agent or I use Hermes Desktop which is not a great piece of software and the remote use is a fragmented ecosystem.

### What you'd like to see

Proposing first-class support for Hermes agent to match other agent support like Goose, Codex, Claude, AMP.

### Why this belongs in Berd itself

This belongs in Berd because the selector needs to have a dropdown for different Hermes gateways. It can't be a skill because the chat needs to run on the remote computer to keep tooling and memory on that computer while also allowing remote execution in that environment.

### Non-goals

- I'm not asking for an open ended ACP support.
- I'm not asking for Hermes feature/skill/memory parity

### Alternatives you considered

I tried to use the remote SSH session in Experimental but that connects only to a Goose agent and not Hermes.

### Mockups, prior art, or other context

_No response_

Start by comparing the existing Goose, Codex, Claude, and AMP agent integrations, then trace the Experimental SSH path and the selector that chooses gateways. Define how Hermes would connect to the remote computer while preserving its tooling and memory. Done means Hermes appears as a selectable gateway for remote sessions without requiring open-ended ACP or feature parity.

Written by the indexing model from the issue text.