Verify kind backend on dory's docker socket

[patrickleet]

Follow-up from the cluster backend abstraction (#70).

The kind backend is designed to serve dory users by running against dory's docker socket:

docker context use dory   # or: export DOCKER_HOST=unix://$HOME/.dory/dory.sock
hops local start --backend kind

This needs a one-time manual verification on a machine with dory installed (not available on the dev machine that produced #70). Research findings so far (from dory source @ v0.2.0):

• dory's own k8s is k3s-in-a-privileged-container on its dockerd, so privileged kind node containers LIKELY work on dory's VM kernel — but unverified.
• Check that kind's extraPortMappings (127.0.0.1:30500) is actually reachable from the macOS host through dory's port forwarding.
• Do NOT use dory's built-in Kubernetes: only 6443 is published, port bindings are fixed at container create, trust config is wiped when k8s is toggled.

Acceptance: hops local start --backend kind + hops local doctor + a docker push localhost:30500/... round-trip green with DOCKER_HOST pointed at dory, or documented findings on why it can't work.

🤖 Generated with Claude Code

[patrickleet]

Update after reading dory's source (fork: patrickleet/dory, v0.2.0):

Dory already auto-forwards every published port of every running container to host 127.0.0.1, re-synced every 3s (AppStore.swift:539 → HostPortForwarder), with an exec-bridge fallback that reaches even loopback-bound bindings inside the engine. So kind's 127.0.0.1:30500 hostPort binding on dory's dockerd should surface on the macOS host with no extra setup — as long as the Dory app is running. This raises confidence that kind-on-dory works out of the box; the remaining unknown is just kind's privileged node containers on dory's VM kernel (k3s-in-container already works there, so likely fine).

Also drafted four upstream specs toward a future native dory backend (extra port publishing on dory-k8s, persistent registries.yaml via the existing home virtiofs share, headless dory k8s enable/disable/status CLI, named dory kubeconfig context) — tracked in the hops KB under specs/dory-*.