refactor(bottles): two-phase cleanup parallel to prepare/launch

cmd_cleanup used to only sweep running containers via `docker ps`,
missing stopped pipelock sidecars and orphaned networks entirely. On
my host the new version surfaced ~10 stranded networks left behind by
SIGKILLed sessions — the kind of thing the old command implied it was
handling.

New shape, symmetric with start:
- BottleCleanupPlan (abstract, in bottles/__init__.py) with `print` +
  `empty` abstract members.
- DockerBottleCleanupPlan (concrete, in bottles/docker.py) carrying
  the resolved tuples of containers and networks.
- BottlePlatform gains abstract prepare_cleanup() + cleanup(plan).
  DockerBottlePlatform implements both:
    - prepare_cleanup: docker ps -a + docker network ls, both
      filtered to ^claude-bottle-, sorted for stable output.
    - cleanup: docker rm -f containers first (they hold the network
      attachment), then docker network rm.
- cmd_cleanup is now ~25 lines: prepare → print → y/N → cleanup.

claude_bottle/cli/cleanup.py

@@ -1,42 +1,31 @@
-"""cleanup: stop and remove all active claude-bottle containers."""
+"""cleanup: stop and remove all orphaned claude-bottle resources
+(containers + networks) left behind by previous bottles."""
 
 from __future__ import annotations
 
-import subprocess
 import sys
 
-from .. import docker as docker_mod
+from ..bottles import get_bottle_platform
 from ..log import info
 from ._common import read_tty_line
 
 
 def cmd_cleanup(_argv: list[str]) -> int:
-    docker_mod.require_docker()
-    result = subprocess.run(
-        ["docker", "ps", "--filter", "name=^claude-bottle-", "--format", "{{.Names}}"],
-        capture_output=True,
-        text=True,
-    )
-    containers = (result.stdout or "").strip()
-    if not containers:
-        info("no active claude-bottle containers")
+    platform = get_bottle_platform()
+    plan = platform.prepare_cleanup()
+
+    if plan.empty:
+        info("no claude-bottle resources to clean up")
         return 0
-    print(file=sys.stderr)
-    for name in containers.splitlines():
-        info(f"found: {name}")
-    print(file=sys.stderr)
+
+    plan.print()
     sys.stderr.write("claude-bottle: remove all of the above? [y/N] ")
     sys.stderr.flush()
     reply = read_tty_line()
     if reply not in ("y", "Y", "yes", "YES"):
         info("aborted")
         return 0
-    for name in containers.splitlines():
-        info(f"removing {name}")
-        subprocess.run(
-            ["docker", "rm", "-f", name],
-            stdout=subprocess.DEVNULL,
-            stderr=subprocess.DEVNULL,
-        )
+
+    platform.cleanup(plan)
     info("done")
     return 0