refactor(cli): split claude_bottle/cli.py into a package

One file per subcommand under claude_bottle/cli/, with shared constants
and the tty helper in _common.py and dispatch in __init__.py. The
public import (from claude_bottle.cli import main) is unchanged, so
the root cli.py entrypoint and the test suite see no surface change.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

claude_bottle/cli/list.py

@@ -0,0 +1,44 @@
+"""list: list available agents or active containers."""
+
+from __future__ import annotations
+
+import argparse
+import subprocess
+
+from .. import docker as docker_mod
+from ..log import info
+from ..manifest import manifest_resolve
+from ._common import PROG, USER_CWD
+
+
+def cmd_list(argv: list[str]) -> int:
+    parser = argparse.ArgumentParser(prog=f"{PROG} list", add_help=True)
+    parser.add_argument("scope", choices=["available", "active"])
+    args = parser.parse_args(argv)
+
+    if args.scope == "available":
+        manifest = manifest_resolve(USER_CWD)
+        for name in (manifest.get("agents") or {}).keys():
+            print(name)
+        return 0
+
+    docker_mod.require_docker()
+    result = subprocess.run(
+        [
+            "docker", "ps",
+            "--filter", "name=^claude-bottle-",
+            "--format", "{{.Names}}\t{{.Status}}",
+        ],
+        capture_output=True,
+        text=True,
+    )
+    containers = (result.stdout or "").strip()
+    if not containers:
+        info("no active claude-bottle containers")
+        return 0
+    print()
+    for line in containers.splitlines():
+        name, _, status = line.partition("\t")
+        info(f"container: {name}  status: {status}")
+    print()
+    return 0