feat(macos): consolidated per-host gateway for the Apple backend (PRD 0070)

Re-enables the macos-container backend on the shared per-host orchestrator +
gateway, replacing the per-bottle companion container removed in #385. This is
the last backend in PRD 0070's roadmap.

Apple Container 1.0.0 forced three departures from the docker shape, each
verified against the live CLI (findings recorded in the networking spike):

- No `--ip`. The address is DHCP-assigned and knowable only once the container
  runs, so the order inverts: gateway up -> run agent -> read its address ->
  register. The identity token is minted by registration and therefore cannot
  be in the agent's run-time env; it rides the proxy URL applied at
  `container exec` time (bare `--env` names keep it off argv).
- No container DNS. The gateway can only be handed the control plane's IP, so
  the orchestrator starts first and the gateway is pointed at its address.
- No `network connect`. Networks are fixed at run time, so the shared host-only
  network is created up front; per-bottle networks would restart the gateway
  on every launch and defeat the consolidation.

The agent runs with `--cap-drop CAP_NET_RAW`: Apple grants NET_RAW by default,
which would let an agent forge a neighbour's source address on the shared
segment. NET_ADMIN is already absent, so this closes the source-address half of
PRD 0070's attribution invariant.

Verified end-to-end on real Apple Container 1.0.0: both images build, the
control plane comes up healthy, the gateway reaches it by IP, and a registered
agent gets 200 for a host in its routes and 403 for one outside them. Bring-up
is idempotent — a second launch does not churn the singletons.

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

bot_bottle/orchestrator/lifecycle.py

@@ -41,7 +41,7 @@ ORCHESTRATOR_IMAGE = os.environ.get(
 ORCHESTRATOR_DOCKERFILE = "Dockerfile.orchestrator"
 # Baked onto the container as a label so `ensure_running` can tell whether the
 # running process is executing the *current* bind-mounted source — see
-# `_source_hash`.
+# `source_hash`.
 ORCHESTRATOR_SOURCE_HASH_LABEL = "bot-bottle-orchestrator-source-hash"
 
 # The repo root is bind-mounted into the control-plane container so
@@ -60,7 +60,7 @@ class OrchestratorStartError(RuntimeError):
     """The orchestrator container did not become healthy within the timeout."""
 
 
-def _source_hash(repo_root: Path) -> str:
+def source_hash(repo_root: Path) -> str:
     """Content hash of the orchestrator's bind-mounted Python source (the
     `bot_bottle` package the control-plane process imports). This only
     changes when the code that would actually run inside the container
@@ -134,17 +134,17 @@ class OrchestratorService:
         proc = run_docker(["docker", "ps", "--filter", f"name=^/{name}$", "--format", "{{.Names}}"])
         return name in proc.stdout.split()
 
-    def _run_orchestrator_container(self, source_hash: str) -> None:
+    def _run_orchestrator_container(self, current_hash: str) -> None:
         """Start the control-plane container (idempotent: clears a stale
         fixed-name container first). Register-only broker → no docker socket.
-        Labels the container with `source_hash` so a later `ensure_running`
-        can detect a real code change (see `_source_hash`)."""
+        Labels the container with `current_hash` so a later `ensure_running`
+        can detect a real code change (see `source_hash`)."""
         run_docker(["docker", "rm", "--force", self._orchestrator_name])
         proc = run_docker([
             "docker", "run", "--detach",
             "--name", self._orchestrator_name,
             "--label", self._orchestrator_label,
-            "--label", f"{ORCHESTRATOR_SOURCE_HASH_LABEL}={source_hash}",
+            "--label", f"{ORCHESTRATOR_SOURCE_HASH_LABEL}={current_hash}",
             "--network", self.network,
             # Host CLI reaches the control plane here; bound to loopback so it
             # is not exposed on the host's external interfaces.
@@ -224,7 +224,7 @@ class OrchestratorService:
         # launch (the prior behaviour) would drop every other active
         # bottle's in-memory egress tokens each time a new bottle starts,
         # since the orchestrator process holds them only in memory (#381).
-        current_hash = _source_hash(self._repo_root)
+        current_hash = source_hash(self._repo_root)
         if self.is_healthy() and self._orchestrator_source_current(current_hash):
             return self.url