Remove the supervise flag; supervise every bottle

Issue #249: in practice the per-bottle `supervise` flag was never
turned off — all bottles should be supervised. Remove the manifest
flag and make the supervise sidecar unconditional, mirroring egress.

- Reject `supervise:` as a removed bottle key with a migration hint.
- Drop the `supervise` field from ManifestBottle and the extends merge.
- prepare_supervise always returns a SupervisePlan; the plan type is
  now non-optional and the per-backend `is None` guards are gone, so
  the supervise daemon, current-config mount, aliases, and MCP
  registration always render.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YcU7nerbg8cVj9R4EkpfLJ

bot_bottle/backend/macos_container/launch.py

@@ -222,9 +222,7 @@ def _stamp_agent_urls(
     sidecar_ip: str,
 ) -> MacosContainerBottlePlan:
     proxy_url = f"http://{sidecar_ip}:{EGRESS_PORT}"
-    supervise_url = ""
-    if plan.supervise_plan is not None:
-        supervise_url = f"http://{sidecar_ip}:{SUPERVISE_PORT}/"
+    supervise_url = f"http://{sidecar_ip}:{SUPERVISE_PORT}/"
     git_gate_url = ""
     if plan.git_gate_plan.upstreams:
         git_gate_url = f"http://{sidecar_ip}:{_GIT_HTTP_PORT}"
@@ -341,11 +339,9 @@ def _sidecar_dns() -> str:
 
 
 def _sidecar_daemons(plan: MacosContainerBottlePlan) -> tuple[str, ...]:
-    daemons = ["egress"]
+    daemons = ["egress", "supervise"]
     if plan.git_gate_plan.upstreams:
         daemons += ["git-gate", "git-http"]
-    if plan.supervise_plan is not None:
-        daemons.append("supervise")
     return tuple(daemons)
 
 
@@ -355,12 +351,11 @@ def _sidecar_env_entries(plan: MacosContainerBottlePlan) -> tuple[str, ...]:
         env.extend(sorted(plan.egress_plan.token_env_map.keys()))
     if plan.git_gate_plan.upstreams:
         env.append(f"BOT_BOTTLE_GIT_GATE_READY_FILE={_GIT_GATE_READY_FILE}")
-    if plan.supervise_plan is not None:
-        env += [
-            f"SUPERVISE_BOTTLE_SLUG={plan.slug}",
-            f"SUPERVISE_QUEUE_DIR={QUEUE_DIR_IN_CONTAINER}",
-            f"SUPERVISE_PORT={SUPERVISE_PORT}",
-        ]
+    env += [
+        f"SUPERVISE_BOTTLE_SLUG={plan.slug}",
+        f"SUPERVISE_QUEUE_DIR={QUEUE_DIR_IN_CONTAINER}",
+        f"SUPERVISE_PORT={SUPERVISE_PORT}",
+    ]
     return tuple(env)
 
 
@@ -383,8 +378,7 @@ def _sidecar_mounts(
         ))
 
     sp = plan.supervise_plan
-    if sp is not None:
-        mounts.append((str(sp.queue_dir), QUEUE_DIR_IN_CONTAINER, False))
+    mounts.append((str(sp.queue_dir), QUEUE_DIR_IN_CONTAINER, False))
 
     return tuple(mounts)