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/backend/macos_container/bottle.py

@@ -52,6 +52,7 @@ class MacosContainerBottle(Bottle):
         terminal_title: str = "",
         terminal_color: str = "",
         agent_workdir: str = "/home/node",
+        exec_env: dict[str, str] | None = None,
     ):
         self.name = container
         self._teardown = teardown
@@ -62,6 +63,15 @@ class MacosContainerBottle(Bottle):
         self.terminal_color = terminal_color
         self.agent_provider_template = agent_provider_template
         self.agent_workdir = agent_workdir
+        # Env applied to the agent process at `container exec` time, on top of
+        # what the container was run with. This is how the identity token
+        # reaches the agent (PRD 0070): registration mints it *after* the
+        # container exists — its source IP is the registration key and Apple
+        # Container assigns that by DHCP — so it cannot be in the run-time env
+        # the way docker's compose spec does it. `container exec --env` wins
+        # over the run-time value, so the token-bearing proxy URL set here
+        # supersedes the token-less one baked in at launch.
+        self._exec_env = dict(exec_env or {})
         self._closed = False
 
     def agent_argv(self, argv: list[str], *, tty: bool = True) -> list[str]:
@@ -74,6 +84,12 @@ class MacosContainerBottle(Bottle):
             )
         )
         container_exec = ["container", "exec"]
+        # Bare env names, same rule as the terminal hints below: the value
+        # stays in the child env `exec_agent` builds and never reaches argv —
+        # the proxy URL here carries the identity token, which `ps` would
+        # otherwise expose to every process on the host.
+        for name in sorted(self._exec_env):
+            container_exec.extend(["--env", name])
         if tty:
             container_exec.extend(["--interactive", "--tty"])
             # Forward terminal capability hints so TUIs can enable modified-key
@@ -94,21 +110,33 @@ class MacosContainerBottle(Bottle):
 
     def exec_agent(self, argv: list[str], *, tty: bool = True) -> int:
         agent_argv = self.agent_argv(argv, tty=tty)
+        # The values behind the bare `--env` names in `agent_argv`. `sh -lc`
+        # below is in this process tree, so the child env reaches `container
+        # exec` either way.
+        env = {**os.environ, **self._exec_env} if self._exec_env else None
         script = (
             exec_shell_script(agent_argv, self.terminal_title, self.terminal_color)
             if tty else None
         )
         if script is None:
-            return subprocess.run(agent_argv, check=False).returncode
-        return subprocess.run(["sh", "-lc", script], check=False).returncode
+            return subprocess.run(agent_argv, env=env, check=False).returncode
+        return subprocess.run(["sh", "-lc", script], env=env, check=False).returncode
 
     def exec(self, script: str, *, user: str = "node") -> ExecResult:
+        # Carry the same exec env the agent gets: provisioning steps run
+        # through here, and a provider whose provision step fetches anything
+        # would egress without the identity token and be denied by /resolve.
+        # Bare `--env NAME` again, so the token stays off argv.
+        argv = ["container", "exec", "--user", user, "--interactive"]
+        for name in sorted(self._exec_env):
+            argv.extend(["--env", name])
+        argv.extend([self.name, "sh", "-s"])
         result = subprocess.run(
-            ["container", "exec", "--user", user, "--interactive",
-             self.name, "sh", "-s"],
+            argv,
             input=script,
             capture_output=True,
             text=True,
+            env={**os.environ, **self._exec_env} if self._exec_env else None,
             check=False,
         )
         return ExecResult(