hive.deepseek IAddon: runs the SSE bridge (hive-vessel.executor.sse), owns
the vessel registry, and
presents on behalf of the dependencies it is told to.

Config (manifest :addon/config merged with runtime config):
  :deepseek/port          bridge port (default 7925, 0 = any)
  :deepseek/host          bind host (default loopback)
  :deepseek/token         shared secret the dsh plugin must send
  :deepseek/presenter-id  id registered on presenter seats (default :deepseek)
  :deepseek/present-on    addon ids whose presenter seat this vessel takes
                          (default #{}: none)

Registry: hive-vessel's standard translators, then the `:vessel/translators`
hook of every injected dependency, then translators added at runtime
through the `:vessel/register-translators!` hook.

Presenter seats: a dependency named in :deepseek/present-on whose hooks
include a key named `register-presenter!` (hive.carto-flow's is one) gets
this vessel's delivery registered under the presenter id, so its frames
reach dsh with no code on either side naming the other. Opt-in, because a
brick (hive-carto-flow-deepseek) registers under :deepseek itself, and two
registrars would replace each other on every mount.

hive's LLM providers as DeepSeek Harness model routes.

hive-mcp's config already names every OpenAI-compatible provider the swarm
uses (`:llm-providers`, each with `:api-url`, `:secret-key`,
`:default-model`, `:available-models`) and where its key lives
(`:secrets`, e.g. "pass:Venice/key"). dsh's `llm-pi-ai` plugin accepts
hand-declared routes of the same shape. This namespace is the projection
from one to the other, so a dsh session runs on the same providers and
models as the swarm without restating them.

Pure. It never reads a key: a route names the environment variable dsh
resolves per request, and `credential-refs` says where a launcher finds
each value. A secret that is not a `pass:` reference is never copied
anywhere; its route is reported as unresolved instead.

SPDX-License-Identifier: MIT

DeepSeek Harness as a hive vessel.

The vessel speaks hive-vessel's :json dialect; its executor is hive-vessel's
SSE bridge, consumed by the dsh browser plugin (dsh/ in this repo), which
paints panels in the right Sidebar, raises notices, opens workspace files
and re-emits `json/event` messages as Cordis events.

Two faces over the same target:
- `target`     -- a hive-vessel target, for plan / dispatch! / broadcast!
- `->vessel`   -- a hive-addon IVessel, for a host's vessel registry; its
                  :delivery capability accepts ops or presentation
                  envelopes and dispatches them through the registry.