refactor(de-sidecar): remove the per-bottle companion-container architecture

The per-agent companion container (the egress/git-gate/supervise data
plane run once per bottle) is the pre-consolidation architecture. Remove
it and disable the backends that still depend on it, per the #385 thread.

- Delete `backend/docker/sidecar_bundle.py`; docker's live path uses the
  consolidated shared gateway, not a per-bottle bundle.
- Disable the firecracker and macos-container backends: their `launch()`
  fails closed (they launched a per-bottle companion; firecracker's
  consolidated relaunch is #354, macos follows). Their `enumerate` return
  empty and `cleanup` drop the companion-container discovery (firecracker
  keeps VMM/run-dir cleanup).
- Fail-close both backends' `egress_apply` reload (it signalled the
  per-bottle container); consolidated egress policy resolves per-request
  against the orchestrator, so gateway-side apply is a follow-up.
- Rename `egress_sidecar_env_entries` → `egress_gateway_env_entries`,
  `SIDECAR_PORTS` → `GATEWAY_PORTS`.
- Move the shared DockerBottlePlan fixture to `tests/unit/_docker_bottle_plan.py`;
  delete tests for the removed launch paths; update cleanup/egress-apply tests.

Docker consolidated launch verified end-to-end (multitenant isolation
integration test passes). macos/firecracker are intentionally disabled.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WBMWTEtQdJ4W5UrWuLHCck

bot_bottle/backend/macos_container/egress_apply.py

@@ -1,36 +1,24 @@
-"""Host-side egress apply for the macos-container backend.
+"""Host-side egress route-apply for the macos-container backend.
 
-Uses `container kill --signal HUP` (Apple Container framework) instead
-of `docker kill` to signal the sidecar bundle.
+The per-bottle companion container this used to signal (`container kill
+--signal HUP <container>`) was removed in the de-sidecar cleanup (#385),
+along with the disabled macOS launch path. Fails closed until the macOS
+backend grows the consolidated gateway.
 """
 
 from __future__ import annotations
 
-import os
-import subprocess
-
-from ...log import warn
 from ..egress_apply import EgressApplicator, EgressApplyError
-from .launch import sidecar_container_name
 
 
 class MacOSContainerEgressApplicator(EgressApplicator):
     def _signal_bundle_reload(self, slug: str) -> None:
-        container = sidecar_container_name(slug)
-        result = subprocess.run(
-            ["container", "kill", "--signal", "HUP", container],
-            capture_output=True, text=True, check=False, env=os.environ,
+        del slug
+        raise EgressApplyError(
+            "live egress route-apply was removed with the per-bottle "
+            "companion container (#385); the macos-container backend is "
+            "disabled until it uses the consolidated gateway."
         )
-        if result.returncode != 0:
-            last_error = (result.stderr or "").strip() or (result.stdout or "").strip()
-            warn(
-                f"egress: routes updated on disk for {slug}, but bundle reload failed: "
-                f"{last_error or 'container kill failed'}"
-            )
-            raise EgressApplyError(
-                f"could not reload egress bundle {container}: "
-                f"{last_error or 'container kill failed'}"
-            )
 
 
 applicator = MacOSContainerEgressApplicator()