feat(docker): split orchestrator and gateway into separate containers (PRD 0070)

Now that #469 got the DB off the data plane, the docker backend runs the
control plane and data plane as two containers instead of the combined
`bot-bottle-infra` container:

  * bot-bottle-orchestrator — the lean control-plane container (image
    Dockerfile.orchestrator, `-m bot_bottle.orchestrator`). Joins the new
    `bot-bottle-orchestrator` control network (`--internal`) only, plus a
    host-loopback publish for the CLI. Sole opener of bot-bottle.db; holds the
    signing key; no CA, no gateway daemons.
  * bot-bottle-orch-gateway — the data-plane container (DockerGateway),
    dual-homed on the agent `bot-bottle-gateway` network AND the control
    network, so it resolves the orchestrator by name
    (http://bot-bottle-orchestrator:8099) while agents — never on the control
    network — have no route to the control plane (the L3 block, not just the
    JWT). Holds the gateway JWT + the mitmproxy CA.

DockerInfraService now orchestrates the pair (builds gateway + orchestrator
images, brings up the orchestrator then the gateway) and exposes gateway_name;
the launch flow attributes agents against the gateway container. DockerGateway
gains a control_network it joins after run. rotate_ca / the CA read target the
gateway container. The combined Dockerfile.infra is no longer built by docker
(firecracker/macOS still use it until their splits).

pyright 0 errors; unit suite green (2273). Integration tests updated for the
two-container shape but need a real-docker run to validate the networking.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bot_bottle/backend/docker/launch.py

@@ -157,10 +157,9 @@ def launch(
         )
 
         # Step 4: install the SHARED gateway CA into the agent (replaces the
-        # per-bottle CA) — read it out of the running gateway. The consolidated
-        # flow runs the gateway data plane inside the per-host infra container
-        # (INFRA_NAME), so read the CA from there, not the legacy standalone
-        # gateway container name.
+        # per-bottle CA) — read it out of the running gateway container
+        # (INFRA_NAME now aliases the gateway container name; the orchestrator,
+        # split into its own container, holds no CA).
         ca_dir = egress_state_dir(plan.slug) / "gateway-ca"
         ca_dir.mkdir(parents=True, exist_ok=True)
         ca_file = ca_dir / "gateway-ca.pem"