feat(cli): add commit command to snapshot running bottle state

Adds `./cli.py commit [<slug>]` which runs `docker commit` on the
active agent container and stores the resulting image tag in per-bottle
state. The next `./cli.py resume <slug>` automatically boots from the
committed snapshot instead of rebuilding from the Dockerfile, preserving
all in-container state across restarts and migrations.

- bottle_state: add write_committed_image / read_committed_image helpers
- docker/util: add commit_container wrapper around `docker commit`
- docker/launch: check for a committed image before the Dockerfile build
  step; fall back to normal build if the image is absent from the daemon
- cli/commit: new command with interactive slug picker; errors clearly on
  non-Docker backends
- 50 new unit tests covering all paths

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot_bottle/cli/__init__.py

@@ -1,6 +1,6 @@
 """Main CLI dispatcher.
 
-Commands: cleanup, edit, info, init, list, resume, start, supervise
+Commands: cleanup, commit, edit, info, init, list, resume, start, supervise
 """
 
 from __future__ import annotations
@@ -12,6 +12,7 @@ from ..manifest import ManifestError
 from ._common import PROG
 from . import list as _list_mod
 from .cleanup import cmd_cleanup
+from .commit import cmd_commit
 from .edit import cmd_edit
 from .info import cmd_info
 from .init import cmd_init
@@ -23,6 +24,7 @@ cmd_list = _list_mod.cmd_list
 
 COMMANDS = {
     "cleanup": cmd_cleanup,
+    "commit": cmd_commit,
     "edit": cmd_edit,
     "info": cmd_info,
     "init": cmd_init,
@@ -37,6 +39,7 @@ def usage() -> None:
     sys.stderr.write(f"usage: {PROG} <command> [args...]\n\n")
     sys.stderr.write("Commands:\n")
     sys.stderr.write("  cleanup   stop and remove all active bot-bottle containers\n")
+    sys.stderr.write("  commit    snapshot a running bottle's container state to a Docker image\n")
     sys.stderr.write("  edit      open an agent in vim for editing\n")
     sys.stderr.write("  info      print env, skills, and prompt details for a named agent\n")
     sys.stderr.write("  init      interactively create a new agent and add it to bot-bottle.json\n")

bot_bottle/cli/commit.py

@@ -0,0 +1,75 @@
+"""commit: freeze a running Docker bottle's container state to a local image.
+
+Runs `docker commit <container> <image-tag>` on the active agent
+container and stores the image tag in per-bottle state so the next
+`./cli.py resume <slug>` boots from that snapshot instead of
+rebuilding from the Dockerfile.
+
+Only the Docker backend is supported. Smolmachines VMs have no
+container-level commit API in the current smolvm CLI surface.
+"""
+
+from __future__ import annotations
+
+import argparse
+
+from ..backend import enumerate_active_agents
+from ..backend.docker.util import commit_container
+from ..bottle_state import mark_preserved, read_metadata, write_committed_image
+from ..log import die, info
+from ._common import PROG
+from . import tui
+
+
+_COMMITTED_IMAGE_PREFIX = "bot-bottle-committed-"
+_DOCKER_BACKENDS = {"docker", ""}
+
+
+def _committed_image_tag(slug: str) -> str:
+    return f"{_COMMITTED_IMAGE_PREFIX}{slug}:latest"
+
+
+def _agent_container_name(slug: str) -> str:
+    return f"bot-bottle-{slug}"
+
+
+def cmd_commit(argv: list[str]) -> int:
+    parser = argparse.ArgumentParser(prog=f"{PROG} commit", add_help=True)
+    parser.add_argument(
+        "slug",
+        nargs="?",
+        default=None,
+        help=(
+            "bottle slug from `cli.py list active` "
+            "(omit to pick interactively)"
+        ),
+    )
+    args = parser.parse_args(argv)
+
+    slug = args.slug
+    if slug is None:
+        active = enumerate_active_agents()
+        if not active:
+            die("no active bottles; start one with `./cli.py start`")
+        choices = [a.slug for a in active]
+        slug = tui.filter_select(choices, title="Select bottle to commit")
+        if slug is None:
+            return 0
+
+    metadata = read_metadata(slug)
+    backend = metadata.backend if metadata else ""
+    if backend not in _DOCKER_BACKENDS:
+        die(
+            f"commit is only supported for the docker backend; "
+            f"bottle {slug!r} uses {backend!r}"
+        )
+
+    container = _agent_container_name(slug)
+    image_tag = _committed_image_tag(slug)
+
+    commit_container(container, image_tag)
+    write_committed_image(slug, image_tag)
+    mark_preserved(slug)
+    info(f"to resume from this snapshot: ./cli.py resume {slug}")
+    info(f"to export for migration:      docker save {image_tag} -o {slug}.tar")
+    return 0