refactor: move bottle_state.py to top-level bot_bottle package

Both docker and smolmachines backends use bottle state helpers.
Moving to bot_bottle/ makes the sharing explicit and removes the
cross-backend dependency (smolmachines importing from ..docker).

All callers updated: docker backend, smolmachines backend, cli
modules, and tests.

bot_bottle/backend/docker/enumerate.py

@@ -15,7 +15,7 @@ from __future__ import annotations
 import subprocess
 
 from .. import ActiveAgent
-from .bottle_state import read_metadata
+from ...bottle_state import read_metadata
 from .compose import compose_project_name, list_active_slugs