feat(orchestrator): slice 13d(i) — containerize the orchestrator (validated on docker)

Real-on-host testing surfaced two issues the unit-mocked slices couldn't:

1. The host (NixOS) firewall DROPS container->host traffic, so a host-process
   orchestrator is unreachable from the gateway container. Fix: run the
   orchestrator AS a container on the shared gateway network (PRD 0070's
   "virtualize the orchestrator") — the gateway reaches it by container name
   over docker DNS (container<->container, no firewall), and the host CLI
   reaches it via a published loopback port.
2. The control plane crashed the connection on a dispatch error (e.g. a
   broker failure) instead of returning 500.

Changes:
- lifecycle: OrchestratorProcess (host process) -> OrchestratorService
  (containers). Runs the control plane in the bundle image with the repo
  bind-mounted (orchestrator is stdlib-only), register-only stub broker so it
  needs NO docker socket (the backend launches agents; the host manages both
  containers). Registry DB persists via a host-root mount. ensure_running is
  an idempotent singleton over both containers.
- gateway: BOT_BOTTLE_ORCHESTRATOR_URL is now the orchestrator's *by-name*
  URL on the shared network (dropped the host.docker.internal hack).
- control_plane: _serve wraps dispatch — a failure returns 500, never crashes
  the connection.
- OrchestratorProcess default broker -> stub (register-only) for docker.

Validated live end-to-end: both containers up, gateway->orchestrator by name
OK, register -> resolve-by-source-IP returns the bottle's policy from inside
the gateway.

pyright 0 errors; pylint 9.83/10; unit suite green (1760 tests; the 13
test_sidecar_init /bin/sleep errors are pre-existing NixOS-local noise).

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

bot_bottle/orchestrator/control_plane.py

@@ -34,6 +34,7 @@ import http.server
 import json
 import os
 import socketserver
+import sys
 import typing
 from urllib.parse import urlsplit
 
@@ -151,12 +152,20 @@ class Handler(http.server.BaseHTTPRequestHandler):
             super().log_message(format, *args)
 
     def _serve(self, method: str) -> None:
-        """Read the request body, dispatch it, and write the JSON reply."""
+        """Read the request body, dispatch it, and write the JSON reply. A
+        dispatch failure (e.g. a broker error) returns a 500 rather than
+        crashing the connection, so one bad request can't take the control
+        plane down for the caller."""
         server = self.server
         assert isinstance(server, ControlPlaneServer)
         length = int(self.headers.get("Content-Length") or 0)
         body = self.rfile.read(length) if length > 0 else b""
-        status, payload = dispatch(server.orchestrator, method, self.path, body)
+        try:
+            status, payload = dispatch(server.orchestrator, method, self.path, body)
+        except Exception as e:  # noqa: BLE001 — the control plane must stay up
+            sys.stderr.write(f"orchestrator: {method} {self.path} failed: {e!r}\n")
+            sys.stderr.flush()
+            status, payload = 500, {"error": f"internal error: {e}"}
         data = json.dumps(payload).encode()
         self.send_response(status)
         self.send_header("Content-Type", "application/json")