diff --git a/claude_bottle/backend/docker/cleanup.py b/claude_bottle/backend/docker/cleanup.py
index 0af9eed..eda7ac5 100644
--- a/claude_bottle/backend/docker/cleanup.py
+++ b/claude_bottle/backend/docker/cleanup.py
@@ -83,11 +83,18 @@ def _list_prefixed_networks() -> list[str]:
     return sorted(set(out))
 
 
-def _list_orphan_state_dirs(live_projects: set[str]) -> list[str]:
+def _list_orphan_state_dirs(
+    live_projects: set[str], protected_identities: set[str],
+) -> list[str]:
     """State identities whose compose project isn't running and
     that don't have a `.preserve` marker. `.preserve` means the
     user (or an auto-preserve-on-crash) wants the state kept for
-    `resume`."""
+    `resume`.
+
+    `protected_identities` is the set of slugs that are live in
+    ANY backend — used so this docker-side check doesn't reap a
+    running smolmachines bottle's state dir (the layout is shared
+    across both backends)."""
     state_root = _supervise.claude_bottle_root() / "state"
     if not state_root.is_dir():
         return []
@@ -99,6 +106,8 @@ def _list_orphan_state_dirs(live_projects: set[str]) -> list[str]:
         project = f"{COMPOSE_PROJECT_PREFIX}{identity}"
         if project in live_projects:
             continue
+        if identity in protected_identities:
+            continue
         if is_preserved(identity):
             continue
         orphans.append(identity)
@@ -106,15 +115,25 @@ def _list_orphan_state_dirs(live_projects: set[str]) -> list[str]:
 
 
 def prepare_cleanup() -> DockerBottleCleanupPlan:
-    """Enumerate everything cleanup will touch. No removals."""
+    """Enumerate everything cleanup will touch. No removals.
+
+    Pulls the union of live identities across backends via
+    `enumerate_active_agents()` so the orphan-state-dir bucket
+    doesn't include slugs whose smolmachines VM is still up."""
     docker_mod.require_docker()
     projects = list_compose_projects()
     project_set = set(projects)
+    # Late import to avoid a circular at module-load time —
+    # the backend package's __init__ imports this module.
+    from .. import enumerate_active_agents
+    protected = {a.slug for a in enumerate_active_agents()}
     return DockerBottleCleanupPlan(
         projects=tuple(projects),
         stray_containers=tuple(_list_prefixed_containers()),
         stray_networks=tuple(_list_prefixed_networks()),
-        orphan_state_dirs=tuple(_list_orphan_state_dirs(project_set)),
+        orphan_state_dirs=tuple(
+            _list_orphan_state_dirs(project_set, protected),
+        ),
     )
 
 
diff --git a/claude_bottle/backend/smolmachines/backend.py b/claude_bottle/backend/smolmachines/backend.py
index d63362d..9947ee5 100644
--- a/claude_bottle/backend/smolmachines/backend.py
+++ b/claude_bottle/backend/smolmachines/backend.py
@@ -8,6 +8,7 @@ from pathlib import Path
 from typing import Generator, Sequence
 
 from .. import ActiveAgent, BottleBackend, BottleSpec
+from . import cleanup as _cleanup
 from . import enumerate as _enumerate
 from . import launch as _launch
 from . import prepare as _prepare
@@ -76,12 +77,10 @@ class SmolmachinesBottleBackend(
         _supervise.provision_supervise(plan, target)
 
     def prepare_cleanup(self) -> SmolmachinesBottleCleanupPlan:
-        return SmolmachinesBottleCleanupPlan()
+        return _cleanup.prepare_cleanup()
 
     def cleanup(self, plan: SmolmachinesBottleCleanupPlan) -> None:
-        del plan
-        # Nothing to clean in chunks 1-3 — see
-        # SmolmachinesBottleCleanupPlan docstring.
+        _cleanup.cleanup(plan)
 
     def enumerate_active(self) -> Sequence[ActiveAgent]:
         return _enumerate.enumerate_active()
diff --git a/claude_bottle/backend/smolmachines/bottle_cleanup_plan.py b/claude_bottle/backend/smolmachines/bottle_cleanup_plan.py
index 7102e4d..664fc0d 100644
--- a/claude_bottle/backend/smolmachines/bottle_cleanup_plan.py
+++ b/claude_bottle/backend/smolmachines/bottle_cleanup_plan.py
@@ -1,13 +1,29 @@
-"""SmolmachinesBottleCleanupPlan — concrete BottleCleanupPlan stub
-(PRD 0023 chunk 1).
+"""SmolmachinesBottleCleanupPlan — concrete BottleCleanupPlan (issue #77).
 
-Chunk 1 always reports nothing-to-clean. Real enumeration —
-orphaned smolvm machines, stranded gvproxy sockets, leftover
-sidecar bundle containers — lands in chunk 4 alongside the
-integration-test sweep that exercises teardown."""
+Tracks the resources `SmolmachinesBottleBackend.cleanup` will
+remove:
+
+  - machines:  smolvm machines whose name starts with
+               `claude-bottle-` (running or stopped). Stopped +
+               deleted via `smolvm machine stop` + `machine delete -f`.
+  - bundles:   docker containers `claude-bottle-sidecars-<slug>`
+               left over from a smolmachines bottle (the bundle's
+               port-forwards stay published on lo0 aliases until
+               the container is gone). Removed via `docker rm -f`.
+  - networks:  docker networks `claude-bottle-bundle-<slug>`
+               attached to the bundles. Removed via
+               `docker network rm`.
+
+Smolmachines state dirs live under the same `~/.claude-bottle/state/`
+path the docker backend uses; the docker backend's
+`prepare_cleanup` already enumerates orphan state dirs and is the
+single source of truth for that bucket (consults
+`enumerate_active_bottles()` so it doesn't reap a live
+smolmachines bottle's dir)."""
 
 from __future__ import annotations
 
+import sys
 from dataclasses import dataclass
 
 from ...log import info
@@ -16,10 +32,24 @@ from .. import BottleCleanupPlan
 
 @dataclass(frozen=True)
 class SmolmachinesBottleCleanupPlan(BottleCleanupPlan):
-    def print(self) -> None:
-        info("smolmachines cleanup: nothing to remove (chunk 4 will "
-             "enumerate orphan machines + gvproxy sockets)")
+    """Resources SmolmachinesBottleBackend.cleanup will remove.
+    Produced by `prepare_cleanup`; sorted so the y/N output is
+    stable."""
+
+    machines: tuple[str, ...] = ()
+    bundles: tuple[str, ...] = ()
+    networks: tuple[str, ...] = ()
 
     @property
     def empty(self) -> bool:
-        return True
+        return not self.machines and not self.bundles and not self.networks
+
+    def print(self) -> None:
+        print(file=sys.stderr)
+        for name in self.machines:
+            info(f"smolvm machine:  {name}")
+        for name in self.bundles:
+            info(f"bundle container:{name}")
+        for name in self.networks:
+            info(f"bundle network:  {name}")
+        print(file=sys.stderr)
diff --git a/claude_bottle/backend/smolmachines/cleanup.py b/claude_bottle/backend/smolmachines/cleanup.py
new file mode 100644
index 0000000..b5bd01a
--- /dev/null
+++ b/claude_bottle/backend/smolmachines/cleanup.py
@@ -0,0 +1,159 @@
+"""Cleanup + active-listing for the smolmachines backend (issue #77).
+
+`prepare_cleanup` enumerates leftover smolmachines resources:
+
+  - smolvm machines (`smolvm machine ls --json`) whose name starts
+    with `claude-bottle-`.
+  - bundle docker containers (`claude-bottle-sidecars-<slug>`).
+  - bundle docker networks (`claude-bottle-bundle-<slug>`).
+
+State dirs live under `~/.claude-bottle/state/<identity>/` —
+shared layout with the docker backend, which has the single
+orphan-state-dir enumerator (it already consults
+`enumerate_active_agents()` so a live smolmachines bottle's dir
+is preserved).
+
+`cleanup` removes everything in the plan: stop + delete each VM,
+force-rm each container, rm each network. Each step is
+best-effort — a failure on one resource doesn't block the others."""
+
+from __future__ import annotations
+
+import json
+import subprocess
+
+from ...log import info, warn
+from . import sidecar_bundle as _bundle
+from . import smolvm as _smolvm
+from .bottle_cleanup_plan import SmolmachinesBottleCleanupPlan
+
+
+# Both names start with the same prefix the launcher uses.
+_VM_PREFIX = "claude-bottle-"
+_BUNDLE_PREFIX = _bundle.bundle_container_name("")          # `claude-bottle-sidecars-`
+_NETWORK_PREFIX = _bundle.bundle_network_name("")           # `claude-bottle-bundle-`
+
+
+def prepare_cleanup() -> SmolmachinesBottleCleanupPlan:
+    """Enumerate every smolmachines-owned resource on the host.
+    No side effects. Returns an empty plan when smolvm isn't on
+    PATH (no machines to reap) — `cleanup` is a no-op in that
+    case too."""
+    machines = _list_claude_bottle_machines()
+    bundles = _list_bundle_containers()
+    networks = _list_bundle_networks()
+    return SmolmachinesBottleCleanupPlan(
+        machines=tuple(sorted(machines)),
+        bundles=tuple(sorted(bundles)),
+        networks=tuple(sorted(networks)),
+    )
+
+
+def cleanup(plan: SmolmachinesBottleCleanupPlan) -> None:
+    """Remove everything in the plan. Order matters: stop VMs
+    first (they hold ports on lo0 aliases via libkrun), then the
+    bundle containers (which hold the host port-forwards), then
+    the networks (which docker won't reap until the containers
+    are gone)."""
+    for name in plan.machines:
+        info(f"stopping smolvm machine {name}")
+        subprocess.run(
+            ["smolvm", "machine", "stop", "--name", name],
+            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+            check=False,
+        )
+        info(f"deleting smolvm machine {name}")
+        r = subprocess.run(
+            ["smolvm", "machine", "delete", "-f", name],
+            capture_output=True, text=True, check=False,
+        )
+        if r.returncode != 0:
+            warn(
+                f"smolvm machine delete -f {name} failed: "
+                f"{(r.stderr or '').strip()}"
+            )
+
+    for name in plan.bundles:
+        info(f"removing bundle container {name}")
+        subprocess.run(
+            ["docker", "rm", "-f", name],
+            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+            check=False,
+        )
+
+    for name in plan.networks:
+        info(f"removing bundle network {name}")
+        r = subprocess.run(
+            ["docker", "network", "rm", name],
+            capture_output=True, text=True, check=False,
+        )
+        if r.returncode != 0 and "no such network" not in (r.stderr or "").lower():
+            warn(
+                f"docker network rm {name} failed: "
+                f"{(r.stderr or '').strip()}"
+            )
+
+
+def _list_claude_bottle_machines() -> list[str]:
+    """All smolvm machines named `claude-bottle-*`, regardless of
+    state (running / stopped / created). Empty when smolvm isn't
+    installed."""
+    if not _smolvm.is_available():
+        return []
+    r = subprocess.run(
+        ["smolvm", "machine", "ls", "--json"],
+        capture_output=True, text=True, check=False,
+    )
+    if r.returncode != 0:
+        return []
+    try:
+        machines = json.loads(r.stdout or "[]")
+    except json.JSONDecodeError:
+        return []
+    return [
+        m["name"] for m in machines
+        if isinstance(m, dict)
+        and m.get("name", "").startswith(_VM_PREFIX)
+    ]
+
+
+def _list_bundle_containers() -> list[str]:
+    """All docker containers named `claude-bottle-sidecars-*`,
+    running or stopped. Empty when docker isn't installed."""
+    # Late import: `backend/__init__` imports this module
+    # transitively via the smolmachines backend.
+    from .. import has_backend
+    if not has_backend("docker"):
+        return []
+    r = subprocess.run(
+        ["docker", "ps", "-a",
+         "--filter", f"name=^{_BUNDLE_PREFIX}",
+         "--format", "{{.Names}}"],
+        capture_output=True, text=True, check=False,
+    )
+    if r.returncode != 0:
+        return []
+    return [
+        line for line in (r.stdout or "").splitlines()
+        if line and line.startswith(_BUNDLE_PREFIX)
+    ]
+
+
+def _list_bundle_networks() -> list[str]:
+    """All docker networks named `claude-bottle-bundle-*`. Empty
+    when docker isn't installed."""
+    from .. import has_backend
+    if not has_backend("docker"):
+        return []
+    r = subprocess.run(
+        ["docker", "network", "ls",
+         "--filter", f"name={_NETWORK_PREFIX}",
+         "--format", "{{.Name}}"],
+        capture_output=True, text=True, check=False,
+    )
+    if r.returncode != 0:
+        return []
+    return [
+        line for line in (r.stdout or "").splitlines()
+        if line and line.startswith(_NETWORK_PREFIX)
+    ]
diff --git a/claude_bottle/cli/cleanup.py b/claude_bottle/cli/cleanup.py
index fe46ae0..eb225f0 100644
--- a/claude_bottle/cli/cleanup.py
+++ b/claude_bottle/cli/cleanup.py
@@ -1,11 +1,16 @@
 """cleanup: stop and remove all orphaned claude-bottle resources.
 
-PRD 0018 chunk 4: backend's prepare_cleanup carries everything in
-one plan — live compose projects (whose `compose down` removes
-containers + networks atomically), legacy stray containers/networks
-that aren't in any project, and orphan state dirs (per-bottle
-state with no live project AND no `.preserve` marker). One prompt,
-one cleanup call.
+Walks every registered backend (docker + smolmachines) so a single
+`./cli.py cleanup` reaps both backends' leftovers — orphaned
+smolvm machines won't survive a docker-only cleanup pass (issue
+addressed alongside #77).
+
+Each backend's `prepare_cleanup` enumerates its own resources;
+docker's `_list_orphan_state_dirs` consults
+`enumerate_active_agents()` for the union of live identities so
+state dirs of running smolmachines bottles aren't reaped. State
+dirs are shared layout, so docker is the single owner of that
+bucket.
 
 State dirs with `.preserve` are intentionally never touched — they
 hold capability-block rebuilds or crash snapshots the operator may
@@ -17,25 +22,37 @@ from __future__ import annotations
 
 import sys
 
-from ..backend import get_bottle_backend
+from ..backend import get_bottle_backend, known_backend_names
 from ..log import info
 from ._common import read_tty_line
 
 
 def cmd_cleanup(_argv: list[str]) -> int:
-    backend = get_bottle_backend()
-    plan = backend.prepare_cleanup()
+    # Order: stable backend iteration so the y/N output is
+    # deterministic across runs.
+    plans = [
+        (name, get_bottle_backend(name)) for name in known_backend_names()
+    ]
+    prepared = [(name, b, b.prepare_cleanup()) for name, b in plans]
 
-    if plan.empty:
+    if all(p.empty for _, _, p in prepared):
         info("no claude-bottle resources to clean up")
         return 0
 
-    plan.print()
+    for name, _, plan in prepared:
+        if plan.empty:
+            continue
+        info(f"--- {name} backend ---")
+        plan.print()
+
     if not _prompt_yes("remove all of the above?"):
         info("cleanup: skipped")
         return 0
 
-    backend.cleanup(plan)
+    for name, backend, plan in prepared:
+        if plan.empty:
+            continue
+        backend.cleanup(plan)
     info("cleanup: done")
     return 0
 
diff --git a/tests/unit/test_cli_cleanup_cross_backend.py b/tests/unit/test_cli_cleanup_cross_backend.py
new file mode 100644
index 0000000..e152966
--- /dev/null
+++ b/tests/unit/test_cli_cleanup_cross_backend.py
@@ -0,0 +1,105 @@
+"""Unit: `cli.py cleanup` walks every backend (issue follow-up).
+
+Asserts cmd_cleanup queries each backend's `prepare_cleanup`,
+combines the y/N output, and runs each backend's `cleanup` when
+the operator confirms.  Mocks the backends and stdin."""
+
+from __future__ import annotations
+
+import sys
+import unittest
+from unittest.mock import patch, MagicMock
+
+from claude_bottle.cli import cleanup as cmd
+
+
+def _make_backend(empty: bool = True):
+    backend = MagicMock()
+    plan = MagicMock(empty=empty)
+    backend.prepare_cleanup.return_value = plan
+    backend.cleanup = MagicMock()
+    return backend, plan
+
+
+class TestCmdCleanup(unittest.TestCase):
+    def test_iterates_every_backend(self):
+        docker, docker_plan = _make_backend(empty=False)
+        smol, smol_plan = _make_backend(empty=False)
+        backends_by_name = {"docker": docker, "smolmachines": smol}
+
+        with patch.object(
+            cmd, "known_backend_names",
+            return_value=("docker", "smolmachines"),
+        ), patch.object(
+            cmd, "get_bottle_backend",
+            side_effect=lambda name: backends_by_name[name],
+        ), patch.object(
+            cmd, "_prompt_yes", return_value=True,
+        ):
+            self.assertEqual(0, cmd.cmd_cleanup([]))
+
+        docker.prepare_cleanup.assert_called_once()
+        smol.prepare_cleanup.assert_called_once()
+        docker.cleanup.assert_called_once_with(docker_plan)
+        smol.cleanup.assert_called_once_with(smol_plan)
+
+    def test_short_circuits_when_all_empty(self):
+        docker, _ = _make_backend(empty=True)
+        smol, _ = _make_backend(empty=True)
+        backends_by_name = {"docker": docker, "smolmachines": smol}
+
+        with patch.object(
+            cmd, "known_backend_names",
+            return_value=("docker", "smolmachines"),
+        ), patch.object(
+            cmd, "get_bottle_backend",
+            side_effect=lambda name: backends_by_name[name],
+        ), patch.object(
+            cmd, "_prompt_yes",
+        ) as prompt:
+            self.assertEqual(0, cmd.cmd_cleanup([]))
+        prompt.assert_not_called()
+        docker.cleanup.assert_not_called()
+        smol.cleanup.assert_not_called()
+
+    def test_abort_at_prompt_runs_nothing(self):
+        docker, _ = _make_backend(empty=False)
+        smol, _ = _make_backend(empty=True)
+        backends_by_name = {"docker": docker, "smolmachines": smol}
+
+        with patch.object(
+            cmd, "known_backend_names",
+            return_value=("docker", "smolmachines"),
+        ), patch.object(
+            cmd, "get_bottle_backend",
+            side_effect=lambda name: backends_by_name[name],
+        ), patch.object(
+            cmd, "_prompt_yes", return_value=False,
+        ):
+            self.assertEqual(0, cmd.cmd_cleanup([]))
+        docker.cleanup.assert_not_called()
+        smol.cleanup.assert_not_called()
+
+    def test_skips_empty_plans_when_others_have_work(self):
+        # docker has work, smolmachines doesn't — only docker.cleanup
+        # is called.
+        docker, docker_plan = _make_backend(empty=False)
+        smol, _ = _make_backend(empty=True)
+        backends_by_name = {"docker": docker, "smolmachines": smol}
+
+        with patch.object(
+            cmd, "known_backend_names",
+            return_value=("docker", "smolmachines"),
+        ), patch.object(
+            cmd, "get_bottle_backend",
+            side_effect=lambda name: backends_by_name[name],
+        ), patch.object(
+            cmd, "_prompt_yes", return_value=True,
+        ):
+            cmd.cmd_cleanup([])
+        docker.cleanup.assert_called_once_with(docker_plan)
+        smol.cleanup.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/unit/test_docker_cleanup.py b/tests/unit/test_docker_cleanup.py
index c2485ac..582ffe4 100644
--- a/tests/unit/test_docker_cleanup.py
+++ b/tests/unit/test_docker_cleanup.py
@@ -44,7 +44,7 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
         self._teardown_fake_home()
 
     def test_no_state_root_returns_empty(self):
-        self.assertEqual([], _list_orphan_state_dirs(set()))
+        self.assertEqual([], _list_orphan_state_dirs(set(), set()))
 
     def test_state_dir_with_no_live_no_preserve_is_orphan(self):
         # Just touch the dir; no metadata, no preserve marker — the
@@ -52,7 +52,7 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
         bottle_state.write_per_bottle_dockerfile("solo-aaa", "FROM x\n")
         self.assertEqual(
             ["solo-aaa"],
-            _list_orphan_state_dirs(set()),
+            _list_orphan_state_dirs(set(), set()),
         )
 
     def test_live_project_skips_dir(self):
@@ -61,7 +61,7 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
         bottle_state.write_per_bottle_dockerfile("live-bbb", "FROM x\n")
         self.assertEqual(
             [],
-            _list_orphan_state_dirs({"claude-bottle-live-bbb"}),
+            _list_orphan_state_dirs({"claude-bottle-live-bbb"}, set()),
         )
 
     def test_preserve_marker_skips_dir(self):
@@ -71,14 +71,14 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
         bottle_state.mark_preserved("kept-ccc")
         self.assertEqual(
             [],
-            _list_orphan_state_dirs(set()),
+            _list_orphan_state_dirs(set(), set()),
         )
 
     def test_preserve_overrides_no_live_project(self):
         # Even without a live project, a preserve marker keeps it.
         bottle_state.write_per_bottle_dockerfile("kept-ddd", "FROM x\n")
         bottle_state.mark_preserved("kept-ddd")
-        self.assertEqual([], _list_orphan_state_dirs(set()))
+        self.assertEqual([], _list_orphan_state_dirs(set(), set()))
 
     def test_mixed_set_categorized_correctly(self):
         bottle_state.write_per_bottle_dockerfile("orphan-eee", "FROM x\n")
@@ -86,7 +86,7 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
         bottle_state.write_per_bottle_dockerfile("kept-ggg", "FROM z\n")
         bottle_state.mark_preserved("kept-ggg")
 
-        result = _list_orphan_state_dirs({"claude-bottle-live-fff"})
+        result = _list_orphan_state_dirs({"claude-bottle-live-fff"}, set())
         self.assertEqual(["orphan-eee"], result)
 
     def test_sorted_output(self):
@@ -94,7 +94,31 @@ class TestOrphanStateDirs(_FakeHomeMixin, unittest.TestCase):
             bottle_state.write_per_bottle_dockerfile(name, "FROM x\n")
         self.assertEqual(
             ["aaa-1", "mmm-1", "zzz-1"],
-            _list_orphan_state_dirs(set()),
+            _list_orphan_state_dirs(set(), set()),
+        )
+
+    def test_protected_identity_skips_dir(self):
+        # `protected_identities` carries slugs that are live in
+        # any backend (smolmachines included). docker's orphan
+        # detection respects them so a running smolmachines
+        # bottle's state dir isn't reaped while the VM is up.
+        bottle_state.write_per_bottle_dockerfile("smol-hhh", "FROM x\n")
+        self.assertEqual(
+            [],
+            _list_orphan_state_dirs(set(), {"smol-hhh"}),
+        )
+
+    def test_protected_overrides_no_live_project(self):
+        # A smolmachines bottle has no docker compose project but
+        # IS in the protected set; the absence of a project
+        # shouldn't cause a reap.
+        bottle_state.write_per_bottle_dockerfile("smol-iii", "FROM x\n")
+        self.assertEqual(
+            [],
+            _list_orphan_state_dirs(
+                {"claude-bottle-something-else"},  # different project up
+                {"smol-iii"},                       # but smol-iii is live
+            ),
         )
 
 
diff --git a/tests/unit/test_smolmachines_cleanup.py b/tests/unit/test_smolmachines_cleanup.py
new file mode 100644
index 0000000..512e5f3
--- /dev/null
+++ b/tests/unit/test_smolmachines_cleanup.py
@@ -0,0 +1,148 @@
+"""Unit: smolmachines backend cleanup (`cleanup.py` +
+`bottle_cleanup_plan.py`).
+
+Tests mock `subprocess.run` + `has_backend` so they execute
+without docker / smolvm on PATH. Each cleanup step verifies argv
+shape; teardown verifies order (machines → bundles → networks)."""
+
+from __future__ import annotations
+
+import subprocess
+import unittest
+from unittest.mock import patch
+
+from claude_bottle import backend as backend_mod
+from claude_bottle.backend.smolmachines import cleanup
+from claude_bottle.backend.smolmachines.bottle_cleanup_plan import (
+    SmolmachinesBottleCleanupPlan,
+)
+
+
+def _ok(stdout: str = "", stderr: str = "") -> subprocess.CompletedProcess:
+    return subprocess.CompletedProcess(
+        args=[], returncode=0, stdout=stdout, stderr=stderr,
+    )
+
+
+class TestPrepareCleanup(unittest.TestCase):
+    def test_empty_when_nothing_running(self):
+        with patch.object(cleanup, "_smolvm") as smolvm, \
+             patch.object(cleanup.subprocess, "run") as run, \
+             patch.object(backend_mod, "has_backend", return_value=True):
+            smolvm.is_available.return_value = True
+            run.return_value = _ok(stdout="[]")
+            plan = cleanup.prepare_cleanup()
+        self.assertTrue(plan.empty)
+
+    def test_lists_machines_bundles_networks(self):
+        def fake_run(argv, *a, **kw):
+            if argv[:3] == ["smolvm", "machine", "ls"]:
+                return _ok(stdout=(
+                    '[{"name":"claude-bottle-a-1","state":"running"},'
+                    ' {"name":"claude-bottle-b-2","state":"created"},'
+                    ' {"name":"unrelated","state":"running"}]'
+                ))
+            if argv[:2] == ["docker", "ps"]:
+                return _ok(stdout=(
+                    "claude-bottle-sidecars-a-1\n"
+                    "claude-bottle-sidecars-b-2\n"
+                ))
+            if argv[:3] == ["docker", "network", "ls"]:
+                return _ok(stdout=(
+                    "claude-bottle-bundle-a-1\n"
+                    "claude-bottle-bundle-b-2\n"
+                ))
+            return _ok()
+
+        with patch.object(cleanup, "_smolvm") as smolvm, \
+             patch.object(cleanup.subprocess, "run", side_effect=fake_run), \
+             patch.object(backend_mod, "has_backend", return_value=True):
+            smolvm.is_available.return_value = True
+            plan = cleanup.prepare_cleanup()
+
+        # `unrelated` filtered out (no claude-bottle- prefix).
+        self.assertEqual(
+            ("claude-bottle-a-1", "claude-bottle-b-2"),
+            plan.machines,
+        )
+        self.assertEqual(
+            ("claude-bottle-sidecars-a-1", "claude-bottle-sidecars-b-2"),
+            plan.bundles,
+        )
+        self.assertEqual(
+            ("claude-bottle-bundle-a-1", "claude-bottle-bundle-b-2"),
+            plan.networks,
+        )
+
+    def test_no_smolvm_means_no_machines(self):
+        with patch.object(cleanup, "_smolvm") as smolvm, \
+             patch.object(cleanup.subprocess, "run", return_value=_ok()), \
+             patch.object(backend_mod, "has_backend", return_value=True):
+            smolvm.is_available.return_value = False
+            plan = cleanup.prepare_cleanup()
+        self.assertEqual((), plan.machines)
+
+
+class TestCleanup(unittest.TestCase):
+    def test_machines_stopped_then_deleted_then_bundles_then_networks(self):
+        plan = SmolmachinesBottleCleanupPlan(
+            machines=("claude-bottle-a-1",),
+            bundles=("claude-bottle-sidecars-a-1",),
+            networks=("claude-bottle-bundle-a-1",),
+        )
+        calls: list[list[str]] = []
+
+        def fake_run(argv, *a, **kw):
+            calls.append(list(argv[:4]))
+            return _ok()
+
+        with patch.object(cleanup.subprocess, "run", side_effect=fake_run):
+            cleanup.cleanup(plan)
+
+        # Stop precedes delete precedes bundle rm precedes network rm.
+        self.assertEqual(
+            ["smolvm", "machine", "stop", "--name"], calls[0],
+        )
+        self.assertEqual(
+            ["smolvm", "machine", "delete", "-f"], calls[1],
+        )
+        self.assertEqual(
+            ["docker", "rm", "-f", "claude-bottle-sidecars-a-1"], calls[2],
+        )
+        self.assertEqual(
+            ["docker", "network", "rm", "claude-bottle-bundle-a-1"], calls[3],
+        )
+
+    def test_failures_are_warnings_not_fatal(self):
+        # smolvm machine delete -f returning non-zero should warn
+        # but continue with bundles + networks. The cleanup is
+        # idempotent on success and tries to remove every resource.
+        plan = SmolmachinesBottleCleanupPlan(
+            machines=("claude-bottle-a-1",),
+            bundles=("claude-bottle-sidecars-a-1",),
+            networks=(),
+        )
+        results = iter([
+            _ok(),  # stop succeeds
+            subprocess.CompletedProcess(args=[], returncode=1, stdout="", stderr="boom"),  # delete fails
+            _ok(),  # bundle rm succeeds
+        ])
+
+        def fake_run(argv, *a, **kw):
+            return next(results)
+
+        with patch.object(cleanup.subprocess, "run", side_effect=fake_run), \
+             patch.object(cleanup, "warn") as warn:
+            cleanup.cleanup(plan)
+        # warn called once for the delete failure.
+        warn.assert_called_once()
+
+    def test_empty_plan_is_noop(self):
+        plan = SmolmachinesBottleCleanupPlan()
+        with patch.object(cleanup.subprocess, "run") as run:
+            cleanup.cleanup(plan)
+        run.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()